Regular Expressions 101

Explanation

Pro

^start of string

Group 1((?:https?:)?\/\/)?

?repeats the group contents below at most once:

Non-Capturing Group(?:https?:)?

?repeats the group contents below at most once:

httpthe literal text http (case sensitive)

s?optionally matches the literal s (115₁₀ / 163₈ / 73₁₆) (case sensitive)

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

Group 2((?:www|m)\.)?

?repeats the group contents below at most once:

Non-Capturing Group(?:www|m)

1st Alternativewww

wwwthe literal text www (case sensitive)

2nd Alternativem

mthe literal m (109₁₀ / 155₈ / 6D₁₆) (case sensitive)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 3((?:youtube\.com|youtu.be))

Non-Capturing Group(?:youtube\.com|youtu.be)

1st Alternativeyoutube\.com

youtubethe literal text youtube (case sensitive)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

comthe literal text com (case sensitive)

2nd Alternativeyoutu.be

yoututhe literal text youtu (case sensitive)

.any character (except for line terminators)

bethe literal text be (case sensitive)

Group 4(\/(?:[\w\-]+\?v=|embed\/|v\/)?)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

Non-Capturing Group(?:[\w\-]+\?v=|embed\/|v\/)?

?repeats the group contents below at most once:

1st Alternative[\w\-]+\?v=

Character Class[\w\-]+

+matches at least one character from the set below:

\wany word character

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

\?the literal ? (63₁₀ / 77₈ / 3F₁₆)

v=the literal text v= (case sensitive)

2nd Alternativeembed\/

embedthe literal text embed (case sensitive)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

3rd Alternativev\/

vthe literal v (118₁₀ / 166₈ / 76₁₆) (case sensitive)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

Group 5([\w\-]+)

Character Class[\w\-]+

+matches at least one character from the set below:

\wany word character

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

Group 6(\S+)?

?repeats the group contents below at most once:

\S+any non-whitespace character, repeated at least once

$end of string, or before its final line terminator

Global pattern flags

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

Match Information

Detailed match information will be displayed here automatically.

Quick Reference

25 tokens

Regular Expression

^((?:https?:)?\/\/)?((?:www|m)\.)?((?:youtube\.com|youtu.be))(\/(?:[\w\-]+\?v=|embed\/|v\/)?)([\w\-]+)(\S+)?$

New

https://www.youtube.com/watch?v=WXTTfsc1j3E

Substitution

https://www.youtube.com/watch?v=WXTTfsc1j3E