Qual é a melhor expressão regular para verificar se uma string é uma URL válida?

Como posso verificar se um dado texto é um endereço URL válido?

O meu conhecimento de Expressões Regulares é básico e não me permite escolher entre as centenas de expressões regulares que já vi na web.

Author: iYoung, 2008-10-02
Source

30 answers

Escrevi o meu padrão URL (na verdade, IRI, internacionalizado) para cumprir com o RFC 3987 (http://www.faqs.org/rfcs/rfc3987.html . estas estão na sintaxe do PCRE.

Para IRIs absoluta (internacionalizada): 

/^[a-z](?:[-a-z0-9\+\.])*:(?:\/\/(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:])*@)?(?:\[(?:(?:(?:[0-9a-f]{1,4}:){6}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|::(?:[0-9a-f]{1,4}:){5}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:[0-9a-f]{1,4})?::(?:[0-9a-f]{1,4}:){4}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:[0-9a-f]{1,4}:[0-9a-f]{1,4})?::(?:[0-9a-f]{1,4}:){3}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:(?:[0-9a-f]{1,4}:){0,2}[0-9a-f]{1,4})?::(?:[0-9a-f]{1,4}:){2}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:(?:[0-9a-f]{1,4}:){0,3}[0-9a-f]{1,4})?::[0-9a-f]{1,4}:(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:(?:[0-9a-f]{1,4}:){0,4}[0-9a-f]{1,4})?::(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:(?:[0-9a-f]{1,4}:){0,5}[0-9a-f]{1,4})?::[0-9a-f]{1,4}|(?:(?:[0-9a-f]{1,4}:){0,6}[0-9a-f]{1,4})?::)|v[0-9a-f]+[-a-z0-9\._~!\$&'\(\)\*\+,;=:]+)\]|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3}|(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=@])*)(?::[0-9]*)?(?:\/(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@]))*)*|\/(?:(?:(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@]))+)(?:\/(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@]))*)*)?|(?:(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@]))+)(?:\/(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@]))*)*|(?!(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@])))(?:\?(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@])|[\x{E000}-\x{F8FF}\x{F0000}-\x{FFFFD}\x{100000}-\x{10FFFD}\/\?])*)?(?:\#(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@])|[\/\?])*)?$/i

Para também permitir íris relativa: 

/^(?:[a-z](?:[-a-z0-9\+\.])*:(?:\/\/(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:])*@)?(?:\[(?:(?:(?:[0-9a-f]{1,4}:){6}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|::(?:[0-9a-f]{1,4}:){5}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:[0-9a-f]{1,4})?::(?:[0-9a-f]{1,4}:){4}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:[0-9a-f]{1,4}:[0-9a-f]{1,4})?::(?:[0-9a-f]{1,4}:){3}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:(?:[0-9a-f]{1,4}:){0,2}[0-9a-f]{1,4})?::(?:[0-9a-f]{1,4}:){2}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:(?:[0-9a-f]{1,4}:){0,3}[0-9a-f]{1,4})?::[0-9a-f]{1,4}:(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:(?:[0-9a-f]{1,4}:){0,4}[0-9a-f]{1,4})?::(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:(?:[0-9a-f]{1,4}:){0,5}[0-9a-f]{1,4})?::[0-9a-f]{1,4}|(?:(?:[0-9a-f]{1,4}:){0,6}[0-9a-f]{1,4})?::)|v[0-9a-f]+[-a-z0-9\._~!\$&'\(\)\*\+,;=:]+)\]|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3}|(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=@])*)(?::[0-9]*)?(?:\/(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@]))*)*|\/(?:(?:(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@]))+)(?:\/(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@]))*)*)?|(?:(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@]))+)(?:\/(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@]))*)*|(?!(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@])))(?:\?(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@])|[\x{E000}-\x{F8FF}\x{F0000}-\x{FFFFD}\x{100000}-\x{10FFFD}\/\?])*)?(?:\#(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@])|[\/\?])*)?|(?:\/\/(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:])*@)?(?:\[(?:(?:(?:[0-9a-f]{1,4}:){6}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|::(?:[0-9a-f]{1,4}:){5}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:[0-9a-f]{1,4})?::(?:[0-9a-f]{1,4}:){4}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:[0-9a-f]{1,4}:[0-9a-f]{1,4})?::(?:[0-9a-f]{1,4}:){3}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:(?:[0-9a-f]{1,4}:){0,2}[0-9a-f]{1,4})?::(?:[0-9a-f]{1,4}:){2}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:(?:[0-9a-f]{1,4}:){0,3}[0-9a-f]{1,4})?::[0-9a-f]{1,4}:(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:(?:[0-9a-f]{1,4}:){0,4}[0-9a-f]{1,4})?::(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:(?:[0-9a-f]{1,4}:){0,5}[0-9a-f]{1,4})?::[0-9a-f]{1,4}|(?:(?:[0-9a-f]{1,4}:){0,6}[0-9a-f]{1,4})?::)|v[0-9a-f]+[-a-z0-9\._~!\$&'\(\)\*\+,;=:]+)\]|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3}|(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=@])*)(?::[0-9]*)?(?:\/(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@]))*)*|\/(?:(?:(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@]))+)(?:\/(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@]))*)*)?|(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=@])+)(?:\/(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@]))*)*|(?!(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@])))(?:\?(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@])|[\x{E000}-\x{F8FF}\x{F0000}-\x{FFFFD}\x{100000}-\x{10FFFD}\/\?])*)?(?:\#(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\._~\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}!\$&'\(\)\*\+,;=:@])|[\/\?])*)?)$/i

Como foram compilados (em PHP): 

<?php

/* Regex convenience functions (character class, non-capturing group) */
function cc($str, $suffix = '', $negate = false) {
    return '[' . ($negate ? '^' : '') . $str . ']' . $suffix;
}
function ncg($str, $suffix = '') {
    return '(?:' . $str . ')' . $suffix;
}

/* Preserved from RFC3986 */

$ALPHA = 'a-z';
$DIGIT = '0-9';
$HEXDIG = $DIGIT . 'a-f';

$sub_delims = '!\\$&\'\\(\\)\\*\\+,;=';
$gen_delims = ':\\/\\?\\#\\[\\]@';
$reserved = $gen_delims . $sub_delims;
$unreserved = '-' . $ALPHA . $DIGIT . '\\._~';

$pct_encoded = '%' . cc($HEXDIG) . cc($HEXDIG);

$dec_octet = ncg(implode('|', array(
    cc($DIGIT),
    cc('1-9') . cc($DIGIT),
    '1' . cc($DIGIT) . cc($DIGIT),
    '2' . cc('0-4') . cc($DIGIT),
    '25' . cc('0-5')
)));

$IPv4address = $dec_octet . ncg('\\.' . $dec_octet, '{3}');

$h16 = cc($HEXDIG, '{1,4}');
$ls32 = ncg($h16 . ':' . $h16 . '|' . $IPv4address);

$IPv6address = ncg(implode('|', array(
    ncg($h16 . ':', '{6}') . $ls32,
    '::' . ncg($h16 . ':', '{5}') . $ls32,
    ncg($h16, '?') . '::' . ncg($h16 . ':', '{4}') . $ls32,
    ncg($h16 . ':' . $h16, '?') . '::' . ncg($h16 . ':', '{3}') . $ls32,
    ncg(ncg($h16 . ':', '{0,2}') . $h16, '?') . '::' . ncg($h16 . ':', '{2}') . $ls32,
    ncg(ncg($h16 . ':', '{0,3}') . $h16, '?') . '::' . $h16 . ':' . $ls32,
    ncg(ncg($h16 . ':', '{0,4}') . $h16, '?') . '::' . $ls32,
    ncg(ncg($h16 . ':', '{0,5}') . $h16, '?') . '::' . $h16,
    ncg(ncg($h16 . ':', '{0,6}') . $h16, '?') . '::',
)));

$IPvFuture = 'v' . cc($HEXDIG, '+') . cc($unreserved . $sub_delims . ':', '+');

$IP_literal = '\\[' . ncg(implode('|', array($IPv6address, $IPvFuture))) . '\\]';

$port = cc($DIGIT, '*');

$scheme = cc($ALPHA) . ncg(cc('-' . $ALPHA . $DIGIT . '\\+\\.'), '*');

/* New or changed in RFC3987 */

$iprivate = '\x{E000}-\x{F8FF}\x{F0000}-\x{FFFFD}\x{100000}-\x{10FFFD}';

$ucschar = '\x{A0}-\x{D7FF}\x{F900}-\x{FDCF}\x{FDF0}-\x{FFEF}' .
    '\x{10000}-\x{1FFFD}\x{20000}-\x{2FFFD}\x{30000}-\x{3FFFD}' .
    '\x{40000}-\x{4FFFD}\x{50000}-\x{5FFFD}\x{60000}-\x{6FFFD}' .
    '\x{70000}-\x{7FFFD}\x{80000}-\x{8FFFD}\x{90000}-\x{9FFFD}' .
    '\x{A0000}-\x{AFFFD}\x{B0000}-\x{BFFFD}\x{C0000}-\x{CFFFD}' .
    '\x{D0000}-\x{DFFFD}\x{E1000}-\x{EFFFD}';

$iunreserved = '-' . $ALPHA . $DIGIT . '\\._~' . $ucschar;

$ipchar = ncg($pct_encoded . '|' . cc($iunreserved . $sub_delims . ':@'));

$ifragment = ncg($ipchar . '|' . cc('\\/\\?'), '*');

$iquery = ncg($ipchar . '|' . cc($iprivate . '\\/\\?'), '*');

$isegment_nz_nc = ncg($pct_encoded . '|' . cc($iunreserved . $sub_delims . '@'), '+');
$isegment_nz = ncg($ipchar, '+');
$isegment = ncg($ipchar, '*');

$ipath_empty = '(?!' . $ipchar . ')';
$ipath_rootless = ncg($isegment_nz) . ncg('\\/' . $isegment, '*');
$ipath_noscheme = ncg($isegment_nz_nc) . ncg('\\/' . $isegment, '*');
$ipath_absolute = '\\/' . ncg($ipath_rootless, '?'); // Spec says isegment-nz *( "/" isegment )
$ipath_abempty = ncg('\\/' . $isegment, '*');

$ipath = ncg(implode('|', array(
    $ipath_abempty,
    $ipath_absolute,
    $ipath_noscheme,
    $ipath_rootless,
    $ipath_empty
))) . ')';

$ireg_name = ncg($pct_encoded . '|' . cc($iunreserved . $sub_delims . '@'), '*');

$ihost = ncg(implode('|', array($IP_literal, $IPv4address, $ireg_name)));
$iuserinfo = ncg($pct_encoded . '|' . cc($iunreserved . $sub_delims . ':'), '*');
$iauthority = ncg($iuserinfo . '@', '?') . $ihost . ncg(':' . $port, '?');

$irelative_part = ncg(implode('|', array(
    '\\/\\/' . $iauthority . $ipath_abempty . '',
    '' . $ipath_absolute . '',
    '' . $ipath_noscheme . '',
    '' . $ipath_empty . ''
)));

$irelative_ref = $irelative_part . ncg('\\?' . $iquery, '?') . ncg('\\#' . $ifragment, '?');

$ihier_part = ncg(implode('|', array(
    '\\/\\/' . $iauthority . $ipath_abempty . '',
    '' . $ipath_absolute . '',
    '' . $ipath_rootless . '',
    '' . $ipath_empty . ''
)));

$absolute_IRI = $scheme . ':' . $ihier_part . ncg('\\?' . $iquery, '?');

$IRI = $scheme . ':' . $ihier_part . ncg('\\?' . $iquery, '?') . ncg('\\#' . $ifragment, '?');

$IRI_reference = ncg($IRI . '|' . $irelative_ref);

Edite 7 de Março de 2011: devido à forma como o PHP lida com as barras invertidas em cadeias cotadas, estas são inutilizáveis por omissão. Vais precisar de uma dupla fuga. onde a barra invertida tem um significado especial na regex. Podes fazer isso assim. 

$escape_backslash = '/(?<!\\)\\(?![\[\]\\\^\$\.\|\*\+\(\)QEnrtaefvdwsDWSbAZzB1-9GX]|x\{[0-9a-f]{1,4}\}|\c[A-Z]|)/';
$absolute_IRI = preg_replace($escape_backslash, '\\\\', $absolute_IRI);
$IRI = preg_replace($escape_backslash, '\\\\', $IRI);
$IRI_reference = preg_replace($escape_backslash, '\\\\', $IRI_reference);
 361
Author: eyelidlessness, 2015-06-26 22:00:07

Acabei de escrever um post no blog para uma grande solução para reconhecer URLs na maioria dos formatos usados, tais como:

A expressão regular utilizada é: 

/((([A-Za-z]{3,9}:(?:\/\/)?)(?:[-;:&=\+\$,\w]+@)?[A-Za-z0-9.-]+|(?:www.|[-;:&=\+\$,\w]+@)[A-Za-z0-9.-]+)((?:\/[\+~%\/.\w-_]*)?\??(?:[-\+=&;%@.\w_]*)#?(?:[\w]*))?)/
No entanto, recomendo-lhe que vá a http://blog.mattheworiordan.com/post/13174566389/url-regular-expression-for-links-with-or-without-the{[25]para ver o exemplo de trabalho.
 127
Author: Matthew O'Riordan, 2016-12-08 07:46:52
Qual plataforma? Se usar. NET, use System.Uri.TryCreate, não é um regex.

Por exemplo: 

static bool IsValidUrl(string urlString)
{
    Uri uri;
    return Uri.TryCreate(urlString, UriKind.Absolute, out uri)
        && (uri.Scheme == Uri.UriSchemeHttp
         || uri.Scheme == Uri.UriSchemeHttps
         || uri.Scheme == Uri.UriSchemeFtp
         || uri.Scheme == Uri.UriSchemeMailto
            /*...*/);
}

// In test fixture...

[Test]
void IsValidUrl_Test()
{
    Assert.True(IsValidUrl("http://www.example.com"));
    Assert.False(IsValidUrl("javascript:alert('xss')"));
    Assert.False(IsValidUrl(""));
    Assert.False(IsValidUrl(null));
}

(graças a @Yoshi pela dica sobre javascript:)

 78
Author: Duncan Smart, 2017-05-23 12:34:50

Eis o que a RegexBuddy usa.

(\b(https?|ftp|file)://)?[-A-Za-z0-9+&@#/%?=~_|!:,.;]+[-A-Za-z0-9+&@#/%=~_|]

Corresponde a estes abaixo (dentro das marcas ** **: 

**http://www.regexbuddy.com**  
**http://www.regexbuddy.com/**  
**http://www.regexbuddy.com/index.html**  
**http://www.regexbuddy.com/index.html?source=library**

Pode obter a RegexBuddy em http://www.regexbuddy.com/download.html.

 51
Author: Keng, 2017-09-12 19:08:25

No que diz respeito a eyelidness {[[7]}' post de resposta que diz: "isto é baseado na minha leitura da especificação URI.": Thanks Eyelidness, Your is the perfect solution I lought, as it is based on the URI spec! Excelente trabalho. :)

Tive de fazer duas alterações. O primeiro a conseguir que a expressão regular corresponda correctamente aos URLs de endereços IP no PHP (v5.2.10) com a função preg_ match ().

Tive de adicionar mais um conjunto de parêntesis à linha acima do "endereço IP" em torno do tubos: 

)|((\d|[1-9]\d|1\d{2}|2[0-4][0-9]|25[0-5])\.){3}(?#
Não sei porquê.

Também reduzi o tamanho mínimo do domínio de topo de 3 para 2 letras para suportar .co.uk e semelhantes.

Código Final: 

/^(https?|ftp):\/\/(?#                                      protocol
)(([a-z0-9$_\.\+!\*\'\(\),;\?&=-]|%[0-9a-f]{2})+(?#         username
)(:([a-z0-9$_\.\+!\*\'\(\),;\?&=-]|%[0-9a-f]{2})+)?(?#      password
)@)?(?#                                                     auth requires @
)((([a-z0-9]\.|[a-z0-9][a-z0-9-]*[a-z0-9]\.)*(?#             domain segments AND
)[a-z][a-z0-9-]*[a-z0-9](?#                                 top level domain  OR
)|((\d|[1-9]\d|1\d{2}|2[0-4][0-9]|25[0-5])\.){3}(?#
    )(\d|[1-9]\d|1\d{2}|2[0-4][0-9]|25[0-5])(?#             IP address
))(:\d+)?(?#                                                port
))(((\/+([a-z0-9$_\.\+!\*\'\(\),;:@&=-]|%[0-9a-f]{2})*)*(?# path
)(\?([a-z0-9$_\.\+!\*\'\(\),;:@&=-]|%[0-9a-f]{2})*)(?#      query string
)?)?)?(?#                                                   path and query string optional
)(#([a-z0-9$_\.\+!\*\'\(\),;:@&=-]|%[0-9a-f]{2})*)?(?#      fragment
)$/i

Esta versão modificada não foi verificada com a especificação URI, por isso não posso garantir a sua conformidade, foi alterada para lidar com URLs em ambientes de rede locais e dois dígitos TLDs, bem como outros tipos de URL Web, e para funcionar melhor na configuração PHP que eu uso.

Como PHP Código: 

define('URL_FORMAT', 
'/^(https?):\/\/'.                                         // protocol
'(([a-z0-9$_\.\+!\*\'\(\),;\?&=-]|%[0-9a-f]{2})+'.         // username
'(:([a-z0-9$_\.\+!\*\'\(\),;\?&=-]|%[0-9a-f]{2})+)?'.      // password
'@)?(?#'.                                                  // auth requires @
')((([a-z0-9]\.|[a-z0-9][a-z0-9-]*[a-z0-9]\.)*'.                      // domain segments AND
'[a-z][a-z0-9-]*[a-z0-9]'.                                 // top level domain  OR
'|((\d|[1-9]\d|1\d{2}|2[0-4][0-9]|25[0-5])\.){3}'.
'(\d|[1-9]\d|1\d{2}|2[0-4][0-9]|25[0-5])'.                 // IP address
')(:\d+)?'.                                                // port
')(((\/+([a-z0-9$_\.\+!\*\'\(\),;:@&=-]|%[0-9a-f]{2})*)*'. // path
'(\?([a-z0-9$_\.\+!\*\'\(\),;:@&=-]|%[0-9a-f]{2})*)'.      // query string
'?)?)?'.                                                   // path and query string optional
'(#([a-z0-9$_\.\+!\*\'\(\),;:@&=-]|%[0-9a-f]{2})*)?'.      // fragment
'$/i');

Aqui está um programa de teste em PHP que valida uma variedade de URLs usando o regex: 

<?php

define('URL_FORMAT',
'/^(https?):\/\/'.                                         // protocol
'(([a-z0-9$_\.\+!\*\'\(\),;\?&=-]|%[0-9a-f]{2})+'.         // username
'(:([a-z0-9$_\.\+!\*\'\(\),;\?&=-]|%[0-9a-f]{2})+)?'.      // password
'@)?(?#'.                                                  // auth requires @
')((([a-z0-9]\.|[a-z0-9][a-z0-9-]*[a-z0-9]\.)*'.                      // domain segments AND
'[a-z][a-z0-9-]*[a-z0-9]'.                                 // top level domain  OR
'|((\d|[1-9]\d|1\d{2}|2[0-4][0-9]|25[0-5])\.){3}'.
'(\d|[1-9]\d|1\d{2}|2[0-4][0-9]|25[0-5])'.                 // IP address
')(:\d+)?'.                                                // port
')(((\/+([a-z0-9$_\.\+!\*\'\(\),;:@&=-]|%[0-9a-f]{2})*)*'. // path
'(\?([a-z0-9$_\.\+!\*\'\(\),;:@&=-]|%[0-9a-f]{2})*)'.      // query string
'?)?)?'.                                                   // path and query string optional
'(#([a-z0-9$_\.\+!\*\'\(\),;:@&=-]|%[0-9a-f]{2})*)?'.      // fragment
'$/i');

/**
 * Verify the syntax of the given URL. 
 * 
 * @access public
 * @param $url The URL to verify.
 * @return boolean
 */
function is_valid_url($url) {
  if (str_starts_with(strtolower($url), 'http://localhost')) {
    return true;
  }
  return preg_match(URL_FORMAT, $url);
}


/**
 * String starts with something
 * 
 * This function will return true only if input string starts with
 * niddle
 * 
 * @param string $string Input string
 * @param string $niddle Needle string
 * @return boolean
 */
function str_starts_with($string, $niddle) {
      return substr($string, 0, strlen($niddle)) == $niddle;
}


/**
 * Test a URL for validity and count results.
 * @param url url
 * @param expected expected result (true or false)
 */

$numtests = 0;
$passed = 0;

function test_url($url, $expected) {
  global $numtests, $passed;
  $numtests++;
  $valid = is_valid_url($url);
  echo "URL Valid?: " . ($valid?"yes":"no") . " for URL: $url. Expected: ".($expected?"yes":"no").". ";
  if($valid == $expected) {
    echo "PASS\n"; $passed++;
  } else {
    echo "FAIL\n";
  }
}

echo "URL Tests:\n\n";

test_url("http://localserver/projects/public/assets/javascript/widgets/UserBoxMenu/widget.css", true);
test_url("http://www.google.com", true);
test_url("http://www.google.co.uk/projects/my%20folder/test.php", true);
test_url("https://myserver.localdomain", true);
test_url("http://192.168.1.120/projects/index.php", true);
test_url("http://192.168.1.1/projects/index.php", true);
test_url("http://projectpier-server.localdomain/projects/public/assets/javascript/widgets/UserBoxMenu/widget.css", true);
test_url("https://2.4.168.19/project-pier?c=test&a=b", true);
test_url("https://localhost/a/b/c/test.php?c=controller&arg1=20&arg2=20", true);
test_url("http://user:password@localhost/a/b/c/test.php?c=controller&arg1=20&arg2=20", true);

echo "\n$passed out of $numtests tests passed.\n\n";

?>

Obrigado mais uma vez à eyelidness {[[7]} para o regex!

 42
Author: meagar, 2013-07-23 18:01:23

Mathias Bynens tem um grande artigo sobre a melhor comparação de um monte de Expressões Regulares: em busca da perfeita validation URL regex

O melhor postado é um pouco longo, mas corresponde a qualquer coisa que você pode jogar nele.

Versão JavaScript 

/^(?:(?:https?|ftp):\/\/)(?:\S+(?::\S*)?@)?(?:(?!(?:10|127)(?:\.\d{1,3}){3})(?!(?:169\.254|192\.168)(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9]+)(?:\.(?:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9]+)*(?:\.(?:[a-z\u00a1-\uffff]{2,}))\.?)(?::\d{2,5})?(?:[/?#]\S*)?$/i

Versão PHP 

_^(?:(?:https?|ftp)://)(?:\S+(?::\S*)?@)?(?:(?!(?:10|127)(?:\.\d{1,3}){3})(?!(?:169\.254|192\.168)(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\x{00a1}-\x{ffff}0-9]-*)*[a-z\x{00a1}-\x{ffff}0-9]+)(?:\.(?:[a-z\x{00a1}-\x{ffff}0-9]-*)*[a-z\x{00a1}-\x{ffff}0-9]+)*(?:\.(?:[a-z\x{00a1}-\x{ffff}]{2,}))\.?)(?::\d{2,5})?(?:[/?#]\S*)?$_iuS
 33
Author: Kiril, 2015-07-30 04:43:24

O post a obter partes de um URL (Regex) discute o processamento de um URL para identificar os seus vários componentes. Se quiser verificar se uma URL está bem formada, deve ser suficiente para as suas necessidades.

Se precisar de verificar se é realmente válido, terá de tentar aceder ao que estiver do outro lado. No entanto, em geral, seria melhor usar uma função que lhe é fornecida pela sua estrutura ou outra biblioteca. Muitas plataformas incluem funções que analisam URLs. Por exemplo, há o módulo urlparse do Python, e no.NET você poderia usar o sistema .Construtor da classe Uri como forma de validar o URL.
 33
Author: Blair Conrad, 2017-08-16 20:02:22

Este pode não ser um trabalho para regexes, mas para ferramentas existentes em sua língua de escolha. você provavelmente quer usar o código existente que já foi escrito, testado e depurado.

Em PHP, utilize o parse_url função.

Perl: URI Módulo

Ruby: URI Módulo

. Net: classe'Uri'

As expressões regulares não são uma varinha mágica que se acena a todos os problemas que envolvem cadeias de caracteres.

 22
Author: Andy Lester, 2013-09-10 16:51:55

Analisador de referência URI não validante

Para efeitos de referência, aqui está a especificação IETF: (TXT | HTML ). Em particular, o Apêndice B. analisando {[11] } uma referência URI com uma expressão Regular demonstra como processar um regex válido. Isto é descrito como,

For an example of a non-validating URI-reference parser that will take any given string and extract the URI components.

Aqui está a regex. indicar: 
 ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
Como outra pessoa disse, É melhor deixar isto para um lib/framework que já está a usar.
 18
Author: Hank Gay, 2018-08-27 05:51:28

Isto vai corresponder a todos os URLs

  • , com ou sem http/https
  • com ou sem www

...incluindo os sub-domínios e as novas extensões de nome de domínio de topo, tais como .Museu, .academia , .Fundação etc. que pode ter até 63 caracteres (não apenas .com , .net ,.info etc.)

(([\w]+:)?//)?(([\d\w]|%[a-fA-f\d]{2,2})+(:([\d\w]|%[a-fA-f\d]{2,2})+)?@)?([\d\w][-\d\w]{0,253}[\d\w]\.)+[\w]{2,63}(:[\d]+)?(/([-+_~.\d\w]|%[a-fA-f\d]{2,2})*)*(\?(&?([-+_~.\d\w]|%[a-fA-f\d]{2,2})=?)*)?(#([-+_~.\d\w]|%[a-fA-f\d]{2,2})*)?

Porque hoje o comprimento máximo do Disponível a extensão de Top-level domain name é de 13 caracteres, tais como .internacional , você pode mudar o número 63 em expressão para 13 para evitar que alguém o use mal.

Como javascript 

var urlreg=/(([\w]+:)?\/\/)?(([\d\w]|%[a-fA-f\d]{2,2})+(:([\d\w]|%[a-fA-f\d]{2,2})+)?@)?([\d\w][-\d\w]{0,253}[\d\w]\.)+[\w]{2,63}(:[\d]+)?(\/([-+_~.\d\w]|%[a-fA-f\d]{2,2})*)*(\?(&?([-+_~.\d\w]|%[a-fA-f\d]{2,2})=?)*)?(#([-+_~.\d\w]|%[a-fA-f\d]{2,2})*)?/;

$('textarea').on('input',function(){
  var url = $(this).val();
  $(this).toggleClass('invalid', urlreg.test(url) == false)
});

$('textarea').trigger('input');
textarea{color:green;}
.invalid{color:red;}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<textarea>http://www.google.com</textarea>
<textarea>http//www.google.com</textarea>
<textarea>googlecom</textarea>
<textarea>https://www.google.com</textarea>

Artigo na Wikipédia: lista de todos os domínios de topo da internet

 11
Author: Besnik Kastrati, 2016-01-26 00:49:08

A melhor expressão regular para o URL para mim seria: 

"(([\w]+:)?//)?(([\d\w]|%[a-fA-F\d]{2,2})+(:([\d\w]|%[a-fA-f\d]{2,2})+)?@)?([\d\w][-\d\w]{0,253}[\d\w]\.)+[\w]{2,4}(:[\d]+)?(/([-+_~.\d\w]|%[a-fA-f\d]{2,2})*)*(\?(&?([-+_~.\d\w]|%[a-fA-f\d]{2,2})=?)*)?(#([-+_~.\d\w]|%[a-fA-f\d]{2,2})*)?"
 10
Author: S.p, 2017-05-06 05:05:03 
        function validateURL(textval) {
            var urlregex = new RegExp(
            "^(http|https|ftp)\://([a-zA-Z0-9\.\-]+(\:[a-zA-Z0-9\.&amp;%\$\-]+)*@)*((25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9])\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0)\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0)\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[0-9])|localhost|([a-zA-Z0-9\-]+\.)*[a-zA-Z0-9\-]+\.(com|edu|gov|int|mil|net|org|biz|arpa|info|name|pro|aero|coop|museum|[a-zA-Z]{2}))(\:[0-9]+)*(/($|[a-zA-Z0-9\.\,\?\'\\\+&amp;%\$#\=~_\-]+))*$");
            return urlregex.test(textval);
        }
Fósforos http://site.com/dir/file.php?var=moo | ftp://user:[email protected]:21/file/dir

Não Coincidências site.com | http://site.com/dir//

 9
Author: user1524615, 2012-10-25 12:57:33 
function validateURL(textval) {
            var urlregex = new RegExp(
            "^(http|https|ftp)\://[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}(:[a-zA-Z0-9]*)?/?([a-zA-Z0-9\-\._\?\,\'/\\\+&amp;%\$#\=~])*$");
            return urlregex.test(textval);
        }
Fósforos http://www.asdah.com/~joe | ftp://ftp.asdah.co.uk:2828/asdah%20asdah.gif | https://asdah.gov/asdh-ah.as
 7
Author: user1524615, 2012-10-25 12:58:38

Se realmente procurar pela correspondência ultimate , provavelmente Encontra-a em "uma boa expressão regular do Url?".

Mas um regex que realmente corresponde a todos os domínios possíveis e permite que tudo o que é permitido de acordo com os RFCs seja horrivelmente longo e ilegível, acredite em mim; -)

 7
Author: Mecki, 2016-01-14 20:59:57
Não consegui encontrar o "regex" que procurava, por isso modifiquei um "regex" para satisfazer as minhas necessidades, e parece que agora funciona bem. As minhas necessidades eram: Aqui o que encontrei, qualquer sugestão é apreciada: 
@Test
    public void testWebsiteUrl(){
        String regularExpression = "((http|ftp|https):\\/\\/)?[\\w\\-_]+(\\.[\\w\\-_]+)+([\\w\\-\\.,@?^=%&amp;:/~\\+#]*[\\w\\-\\@?^=%&amp;/~\\+#])?";

        assertTrue("www.google.com".matches(regularExpression));
        assertTrue("www.google.co.uk".matches(regularExpression));
        assertTrue("http://www.google.com".matches(regularExpression));
        assertTrue("http://www.google.co.uk".matches(regularExpression));
        assertTrue("https://www.google.com".matches(regularExpression));
        assertTrue("https://www.google.co.uk".matches(regularExpression));
        assertTrue("google.com".matches(regularExpression));
        assertTrue("google.co.uk".matches(regularExpression));
        assertTrue("google.mu".matches(regularExpression));
        assertTrue("mes.intnet.mu".matches(regularExpression));
        assertTrue("cse.uom.ac.mu".matches(regularExpression));

        assertTrue("http://www.google.com/path".matches(regularExpression));
        assertTrue("http://subdomain.web-site.com/cgi-bin/perl.cgi?key1=value1&key2=value2e".matches(regularExpression));
        assertTrue("http://www.google.com/?queryparam=123".matches(regularExpression));
        assertTrue("http://www.google.com/path?queryparam=123".matches(regularExpression));

        assertFalse("www..dr.google".matches(regularExpression));

        assertFalse("www:google.com".matches(regularExpression));

        assertFalse("https://[email protected]".matches(regularExpression));

        assertFalse("https://www.google.com\"".matches(regularExpression));
        assertFalse("https://www.google.com'".matches(regularExpression));

        assertFalse("http://www.google.com/path'".matches(regularExpression));
        assertFalse("http://subdomain.web-site.com/cgi-bin/perl.cgi?key1=value1&key2=value2e'".matches(regularExpression));
        assertFalse("http://www.google.com/?queryparam=123'".matches(regularExpression));
        assertFalse("http://www.google.com/path?queryparam=12'3".matches(regularExpression));

    }
 6
Author: thermz, 2013-06-19 07:53:23
Eu escrevi uma versão bacana que você pode executar.

Corresponde aos seguintes urls (O que é bom o suficiente para me) 

public static void main(args){
        String url = "go to http://www.m.abut.ly/abc its awesome"
        url = url.replaceAll(/https?:\/\/w{0,3}\w*?\.(\w*?\.)?\w{2,3}\S*|www\.(\w*?\.)?\w*?\.\w{2,3}\S*|(\w*?\.)?\w*?\.\w{2,3}[\/\?]\S*/ , { it ->
            "woof${it}woof"
        })
        println url

    }

Http://google.com

Http://google.com/help.php

Http://google.com/help.php?a=5

Http://www.google.com

Http://www.google.com/help.php

Http://www.google.com?a=5

Google. com? a=5

Google.com/help.php

Google.com/help.php?a=5

Http://www.m.google.com/help.php?a=5 (e todos os seus permutações)

Www.m.google.com/help.php?a=5 (e todas as suas permutações)

M.google.com/help.php?a=5 (e todas as suas permutações)

A coisa importante para quaisquer urls que não começam com http ou www é que eles devem incluir a / ou ?

Aposto que isto pode ser alterado um pouco mais, mas faz um bom trabalho por ser tão curto e compacto... porque podes dividi-lo em 3:

Encontre qualquer coisa que comece por http: https?: / / w{0,3}\W*?.\w {2,3}\S *

Encontre qualquer coisa que comece com www: www.o quê?.\w {2,3}\S *

Ou encontrar algo que tenha de ter um texto, depois um ponto, depois, pelo menos, duas letras e depois uma ? ou: \w*?.\w {2,3} [ / \?] \S *

 5
Author: Christopher Rivera, 2012-12-04 23:18:06

Uso esta expressão regular: 

((https?:)?//)?(([\d\w]|%[a-fA-f\d]{2,2})+(:([\d\w]|%[a-fA-f\d]{2,2})+)?@)?([\d\w][-\d\w]{0,253}[\d\w]\.)+[\w]{2,63}(:[\d]+)?(/([-+_~.\d\w]|%[a-fA-f\d]{2,2})*)*(\?(&?([-+_~.\d\w]|%[a-fA-f\d]{2,2})=?)*)?(#([-+_~.\d\w]|%[a-fA-f\d]{2,2})*)?

Para suportar ambos: 

http://stackoverflow.com
https://stackoverflow.com

E: 

//stackoverflow.com
 5
Author: Mikael Engver, 2014-08-28 00:55:01
Tenho estado a trabalhar num artigo em profundidade a discutir a validação URI usando expressões regulares. É baseado em RFC3986.

Validação de URI de Expressão Regular

Embora o artigo ainda não esteja completo, eu criei uma função PHP que faz um bom trabalho de validar URLs de HTTP e FTP. Aqui está a versão atual: 

// function url_valid($url) { Rev:20110423_2000
//
// Return associative array of valid URI components, or FALSE if $url is not
// RFC-3986 compliant. If the passed URL begins with: "www." or "ftp.", then
// "http://" or "ftp://" is prepended and the corrected full-url is stored in
// the return array with a key name "url". This value should be used by the caller.
//
// Return value: FALSE if $url is not valid, otherwise array of URI components:
// e.g.
// Given: "http://www.jmrware.com:80/articles?height=10&width=75#fragone"
// Array(
//    [scheme] => http
//    [authority] => www.jmrware.com:80
//    [userinfo] =>
//    [host] => www.jmrware.com
//    [IP_literal] =>
//    [IPV6address] =>
//    [ls32] =>
//    [IPvFuture] =>
//    [IPv4address] =>
//    [regname] => www.jmrware.com
//    [port] => 80
//    [path_abempty] => /articles
//    [query] => height=10&width=75
//    [fragment] => fragone
//    [url] => http://www.jmrware.com:80/articles?height=10&width=75#fragone
// )
function url_valid($url) {
    if (strpos($url, 'www.') === 0) $url = 'http://'. $url;
    if (strpos($url, 'ftp.') === 0) $url = 'ftp://'. $url;
    if (!preg_match('/# Valid absolute URI having a non-empty, valid DNS host.
        ^
        (?P<scheme>[A-Za-z][A-Za-z0-9+\-.]*):\/\/
        (?P<authority>
          (?:(?P<userinfo>(?:[A-Za-z0-9\-._~!$&\'()*+,;=:]|%[0-9A-Fa-f]{2})*)@)?
          (?P<host>
            (?P<IP_literal>
              \[
              (?:
                (?P<IPV6address>
                  (?:                                                (?:[0-9A-Fa-f]{1,4}:){6}
                  |                                                ::(?:[0-9A-Fa-f]{1,4}:){5}
                  | (?:                          [0-9A-Fa-f]{1,4})?::(?:[0-9A-Fa-f]{1,4}:){4}
                  | (?:(?:[0-9A-Fa-f]{1,4}:){0,1}[0-9A-Fa-f]{1,4})?::(?:[0-9A-Fa-f]{1,4}:){3}
                  | (?:(?:[0-9A-Fa-f]{1,4}:){0,2}[0-9A-Fa-f]{1,4})?::(?:[0-9A-Fa-f]{1,4}:){2}
                  | (?:(?:[0-9A-Fa-f]{1,4}:){0,3}[0-9A-Fa-f]{1,4})?::   [0-9A-Fa-f]{1,4}:
                  | (?:(?:[0-9A-Fa-f]{1,4}:){0,4}[0-9A-Fa-f]{1,4})?::
                  )
                  (?P<ls32>[0-9A-Fa-f]{1,4}:[0-9A-Fa-f]{1,4}
                  | (?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}
                       (?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)
                  )
                |   (?:(?:[0-9A-Fa-f]{1,4}:){0,5}[0-9A-Fa-f]{1,4})?::   [0-9A-Fa-f]{1,4}
                |   (?:(?:[0-9A-Fa-f]{1,4}:){0,6}[0-9A-Fa-f]{1,4})?::
                )
              | (?P<IPvFuture>[Vv][0-9A-Fa-f]+\.[A-Za-z0-9\-._~!$&\'()*+,;=:]+)
              )
              \]
            )
          | (?P<IPv4address>(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}
                               (?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))
          | (?P<regname>(?:[A-Za-z0-9\-._~!$&\'()*+,;=]|%[0-9A-Fa-f]{2})+)
          )
          (?::(?P<port>[0-9]*))?
        )
        (?P<path_abempty>(?:\/(?:[A-Za-z0-9\-._~!$&\'()*+,;=:@]|%[0-9A-Fa-f]{2})*)*)
        (?:\?(?P<query>       (?:[A-Za-z0-9\-._~!$&\'()*+,;=:@\\/?]|%[0-9A-Fa-f]{2})*))?
        (?:\#(?P<fragment>    (?:[A-Za-z0-9\-._~!$&\'()*+,;=:@\\/?]|%[0-9A-Fa-f]{2})*))?
        $
        /mx', $url, $m)) return FALSE;
    switch ($m['scheme']) {
    case 'https':
    case 'http':
        if ($m['userinfo']) return FALSE; // HTTP scheme does not allow userinfo.
        break;
    case 'ftps':
    case 'ftp':
        break;
    default:
        return FALSE;   // Unrecognized URI scheme. Default to FALSE.
    }
    // Validate host name conforms to DNS "dot-separated-parts".
    if ($m['regname']) { // If host regname specified, check for DNS conformance.
        if (!preg_match('/# HTTP DNS host name.
            ^                      # Anchor to beginning of string.
            (?!.{256})             # Overall host length is less than 256 chars.
            (?:                    # Group dot separated host part alternatives.
              [A-Za-z0-9]\.        # Either a single alphanum followed by dot
            |                      # or... part has more than one char (63 chars max).
              [A-Za-z0-9]          # Part first char is alphanum (no dash).
              [A-Za-z0-9\-]{0,61}  # Internal chars are alphanum plus dash.
              [A-Za-z0-9]          # Part last char is alphanum (no dash).
              \.                   # Each part followed by literal dot.
            )*                     # Zero or more parts before top level domain.
            (?:                    # Explicitly specify top level domains.
              com|edu|gov|int|mil|net|org|biz|
              info|name|pro|aero|coop|museum|
              asia|cat|jobs|mobi|tel|travel|
              [A-Za-z]{2})         # Country codes are exactly two alpha chars.
              \.?                  # Top level domain can end in a dot.
            $                      # Anchor to end of string.
            /ix', $m['host'])) return FALSE;
    }
    $m['url'] = $url;
    for ($i = 0; isset($m[$i]); ++$i) unset($m[$i]);
    return $m; // return TRUE == array of useful named $matches plus the valid $url.
}

Esta função utiliza dois regexos; um para corresponder a um subconjunto de URIs genéricos válidos (os absolutos com um a máquina não-vazia), e um segundo para validar o nome da máquina DNS "dot-separated-parts". Embora esta função valida atualmente apenas os esquemas HTTP e FTP, ela é estruturada de modo que pode ser facilmente estendida para lidar com outros esquemas.

 4
Author: ridgerunner, 2011-04-24 03:24:04
Este funciona muito bem para mim. (https?|ftp)://(www\d?|[a-zA-Z0-9]+)?\.[a-zA-Z0-9-]+(\:|\.)([a-zA-Z0-9.]+|(\d+)?)([/?:].*)?
 3
Author: Shantonu, 2014-01-17 17:38:34
Aqui está uma versão Java do Código Fonte Android. Este é o melhor que encontrei. 
public static final Matcher WEB  = Pattern.compile(new StringBuilder()                 
.append("((?:(http|https|Http|Https|rtsp|Rtsp):")                      
.append("\\/\\/(?:(?:[a-zA-Z0-9\\$\\-\\_\\.\\+\\!\\*\\'\\(\\)")                         
.append("\\,\\;\\?\\&\\=]|(?:\\%[a-fA-F0-9]{2})){1,64}(?:\\:(?:[a-zA-Z0-9\\$\\-\\_")                         
.append("\\.\\+\\!\\*\\'\\(\\)\\,\\;\\?\\&\\=]|(?:\\%[a-fA-F0-9]{2})){1,25})?\\@)?)?")                         
.append("((?:(?:[a-zA-Z0-9][a-zA-Z0-9\\-]{0,64}\\.)+")   // named host                            
.append("(?:")   // plus top level domain                         
.append("(?:aero|arpa|asia|a[cdefgilmnoqrstuwxz])")                         
.append("|(?:biz|b[abdefghijmnorstvwyz])")                         
.append("|(?:cat|com|coop|c[acdfghiklmnoruvxyz])")                         
.append("|d[ejkmoz]")                         
.append("|(?:edu|e[cegrstu])")                         
.append("|f[ijkmor]")                         
.append("|(?:gov|g[abdefghilmnpqrstuwy])")                         
.append("|h[kmnrtu]")                         
.append("|(?:info|int|i[delmnoqrst])")                         
.append("|(?:jobs|j[emop])")                         
.append("|k[eghimnrwyz]")                         
.append("|l[abcikrstuvy]")                         
.append("|(?:mil|mobi|museum|m[acdghklmnopqrstuvwxyz])")                         
.append("|(?:name|net|n[acefgilopruz])")                         
.append("|(?:org|om)")                         
.append("|(?:pro|p[aefghklmnrstwy])")                         
.append("|qa")                         
.append("|r[eouw]")                         
.append("|s[abcdeghijklmnortuvyz]")                         
.append("|(?:tel|travel|t[cdfghjklmnoprtvwz])")                         
.append("|u[agkmsyz]")                         
.append("|v[aceginu]")                         
.append("|w[fs]")                         
.append("|y[etu]")                         
.append("|z[amw]))")                         
.append("|(?:(?:25[0-5]|2[0-4]") // or ip address                                                 
.append("[0-9]|[0-1][0-9]{2}|[1-9][0-9]|[1-9])\\.(?:25[0-5]|2[0-4][0-9]")                             
.append("|[0-1][0-9]{2}|[1-9][0-9]|[1-9]|0)\\.(?:25[0-5]|2[0-4][0-9]|[0-1]")                         
.append("[0-9]{2}|[1-9][0-9]|[1-9]|0)\\.(?:25[0-5]|2[0-4][0-9]|[0-1][0-9]{2}")                         
.append("|[1-9][0-9]|[0-9])))")                         
.append("(?:\\:\\d{1,5})?)") // plus option port number                             
.append("(\\/(?:(?:[a-zA-Z0-9\\;\\/\\?\\:\\@\\&\\=\\#\\~")  // plus option query params                         
.append("\\-\\.\\+\\!\\*\\'\\(\\)\\,\\_])|(?:\\%[a-fA-F0-9]{2}))*)?")                         
.append("(?:\\b|$)").toString()                 
).matcher("");
 3
Author: kash, 2015-02-15 14:49:19

Encontrei o seguinte Regex para URLs, testado com sucesso com 500 + URLs:

/\b(?:(?:https?|ftp):\/\/)(?:\S+(?::\S*)?@)?(?:(?!10(?:\.\d{1,3}){3})(?!127(?:\.\d{1,3}){3})(?!169\.254(?:\.\d{1,3}){2})(?!192\.168(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\x{00a1}-\x{ffff}0-9]+-?)*[a-z\x{00a1}-\x{ffff}0-9]+)(?:\.(?:[a-z\x{00a1}-\x{ffff}0-9]+-?)*[a-z\x{00a1}-\x{ffff}0-9]+)*(?:\.(?:[a-z\x{00a1}-\x{ffff}]{2,})))(?::\d{2,5})?(?:\/[^\s]*)?\b/gi

sei que parece feio, mas o bom é que funciona. :)

Explanation and demo with 581 random URLs on regex101.

Fonte: em busca da expressão perfeita de validação de URL

 3
Author: Rahul Desai, 2015-10-16 14:11:27

Tentei formular a minha versão de url. Minha exigência era capturar instâncias em uma String onde possível url pode ser cse.uom.ac.mu -notando que não é precedido por http nem www 

String regularExpression = "((((ht{2}ps?://)?)((w{3}\\.)?))?)[^.&&[a-zA-Z0-9]][a-zA-Z0-9.-]+[^.&&[a-zA-Z0-9]](\\.[a-zA-Z]{2,3})";

assertTrue("www.google.com".matches(regularExpression));
assertTrue("www.google.co.uk".matches(regularExpression));
assertTrue("http://www.google.com".matches(regularExpression));
assertTrue("http://www.google.co.uk".matches(regularExpression));
assertTrue("https://www.google.com".matches(regularExpression));
assertTrue("https://www.google.co.uk".matches(regularExpression));
assertTrue("google.com".matches(regularExpression));
assertTrue("google.co.uk".matches(regularExpression));
assertTrue("google.mu".matches(regularExpression));
assertTrue("mes.intnet.mu".matches(regularExpression));
assertTrue("cse.uom.ac.mu".matches(regularExpression));

//cannot contain 2 '.' after www
assertFalse("www..dr.google".matches(regularExpression));

//cannot contain 2 '.' just before com
assertFalse("www.dr.google..com".matches(regularExpression));

// to test case where url www must be followed with a '.'
assertFalse("www:google.com".matches(regularExpression));

// to test case where url www must be followed with a '.'
//assertFalse("http://wwwe.google.com".matches(regularExpression));

// to test case where www must be preceded with a '.'
assertFalse("https://[email protected]".matches(regularExpression));
 2
Author: Ashish, 2012-12-06 08:32:52

Para o Python, este é o URL actual que valida a regex usada no Django 1.5.1: 

import re
regex = re.compile(
        r'^(?:http|ftp)s?://'  # http:// or https://
        r'(?:(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+(?:[A-Z]{2,6}\.?|[A-Z0-9-]{2,}\.?)|'  # domain...
        r'localhost|'  # localhost...
        r'\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}|'  # ...or ipv4
        r'\[?[A-F0-9]*:[A-F0-9:]+\]?)'  # ...or ipv6
        r'(?::\d+)?'  # optional port
        r'(?:/?|[/?]\S+)$', re.IGNORECASE)

Isto faz tanto os endereços ipv4 e ipv6, bem como as portas e obter parâmetros.

Encontrado no código aqui , linha 44.

 2
Author: Ewan, 2013-05-07 18:14:33

O que há de errado com o FILTER_VALIDATE_URL simples e simples ?

 $url = "http://www.example.com";

if(!filter_var($url, FILTER_VALIDATE_URL))
  {
  echo "URL is not valid";
  }
else
  {
  echo "URL is valid";
  }

Eu sei que não é exactamente a questão, mas fez o trabalho para mim quando precisava de validar urls, por isso pensei que poderia ser útil para outros que se deparem com este post à procura da mesma coisa

 2
Author: jojojohn, 2013-06-19 00:48:36

O seguinte RegEx funcionará: 

"@((((ht)|(f))tp[s]?://)|(www\.))([a-z][-a-z0-9]+\.)?([a-z][-a-z0-9]+\.)?[a-z][-a-z0-9]+\.[a-z]+[/]?[a-z0-9._\/~#&=;%+?-]*@si"
 2
Author: Mohammad Anini, 2013-10-09 19:21:04

Para comodidade, aqui está uma expressão regular para URL ' s que também irá corresponder ao localhost, onde é mais provável que tenha portos do que .com ou semelhantes.

(http(s)?:\/\/.)?(www\.)?[-a-zA-Z0-9@:%._\+~#=]{2,256}(\.[a-z]{2,6}|:[0-9]{3,4})\b([-a-zA-Z0-9@:%_\+.~#?&\/\/=]*)
 2
Author: miphe, 2014-12-09 12:59:00

Não especificas que língua estás a usar. Se PHP é, há uma função nativa para isso: 

$url = 'http://www.yoururl.co.uk/sub1/sub2/?param=1&param2/';

if ( ! filter_var( $url, FILTER_VALIDATE_URL ) ) {
    // Wrong
}
else {
    // Valid
}

Devolve os dados filtrados ou devolve falso se o filtro falhar.

Vê aqui.>>

Espero que ajude.
 2
Author: Fredmat, 2015-05-14 13:19:38
Espero que seja útil para ti... 
^(http|https):\/\/+[\www\d]+\.[\w]+(\/[\w\d]+)?
 2
Author: Divya-Systematix, 2018-01-23 20:25:59

Este é um tópico bastante antigo agora e a pergunta pede um validador de URL baseado em regex. Esbarrei no fio da navalha enquanto procurava precisamente a mesma coisa. Embora possa ser possível escrever um regex realmente abrangente para validar URLs que acabei por resolver de outra forma de fazer as coisas-usando a função PHP parse_url .

Devolve booleano false se o url não puder ser processado. Caso contrário, devolve o esquema, o host e outras informações. Isto pode muito bem não é suficiente para uma verificação URL abrangente por si só, mas pode ser perfurado para análise posterior. Se a intenção é simplesmente pegar typos, esquemas inválidos etc é perfeitamente adequado.

 1
Author: DroidOS, 2012-10-24 12:06:38

Verificar a regex URL seria: 

^http(s{0,1})://[a-zA-Z0-9_/\\-\\.]+\\.([A-Za-z/]{2,5})[a-zA-Z0-9_/\\&\\?\\=\\-\\.\\~\\%]*
 1
Author: Reetika, 2013-12-12 11:27:45