Regular Expressions 101

1st Alternative\[(?:[a-zA-Z0-9]{0,4}:?){1,8}\]

\[the literal [ (91₁₀ / 133₈ / 5B₁₆)

Non-Capturing Group(?:[a-zA-Z0-9]{0,4}:?){1,8}

{1,8}repeats the group contents below between 1 and 8 times:

Character Class[a-zA-Z0-9]{0,4}

{0,4}matches between 0 and 4 characters from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

:?optionally matches the literal : (58₁₀ / 72₈ / 3A₁₆)

\]the literal ] (93₁₀ / 135₈ / 5D₁₆)

2nd Alternative\[(?:[a-zA-Z0-9]{0,4}:?){1,4}(?:[0-9]{1,3}\.){3}[0-9]{1,3}\]

\[the literal [ (91₁₀ / 133₈ / 5B₁₆)

Non-Capturing Group(?:[a-zA-Z0-9]{0,4}:?){1,4}

{1,4}repeats the group contents below between 1 and 4 times:

Character Class[a-zA-Z0-9]{0,4}

{0,4}matches between 0 and 4 characters from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

:?optionally matches the literal : (58₁₀ / 72₈ / 3A₁₆)

Non-Capturing Group(?:[0-9]{1,3}\.){3}

{3}repeats the group contents below exactly 3 times:

Character Class[0-9]{1,3}

{1,3}matches between 1 and 3 characters from the set below:

0-9one character from 0 (48₁₀) to 9 (57₁₀)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Character Class[0-9]{1,3}

{1,3}matches between 1 and 3 characters from the set below:

0-9one character from 0 (48₁₀) to 9 (57₁₀)

\]the literal ] (93₁₀ / 135₈ / 5D₁₆)

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

\[(?:[a-zA-Z0-9]{0,4}:?){1,8}\]|\[(?:[a-zA-Z0-9]{0,4}:?){1,4}(?:[0-9]{1,3}\.){3}[0-9]{1,3}\]

Test String
New

[::1]
[:a:1]
[:bh:lh:1]
[1:1:fEd1:1:abdc:1]
[::ffff:192.0.2.128]
[0000:0000:0000:0000:0000:0000:0000:0001]
[2001:0db8:0000:0000:0000:ff00:0042:8329]
[2001:db8:0:0:0:ff00:42:8329]
[2001:db8::ff00:42:8329]
[2001:0db8:0000:0000:0000:ff00:0042:8329]

Regular Expression

Test StringNew

SubstitutionProcessing...

Test String
New

Substitution
Processing...