Regular Expressions 101

^start of line

.+any character (except for line terminators), repeated at least once

Group 1(video\/|\/watch\?v=|embed\/)

1st Alternativevideo\/

videothe literal text video (case insensitive)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

2nd Alternative\/watch\?v=

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

watchthe literal text watch (case insensitive)

\?the literal ? (63₁₀ / 77₈ / 3F₁₆)

v=the literal text v= (case insensitive)

3rd Alternativeembed\/

embedthe literal text embed (case insensitive)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

Group 2([a-z0-9_?=-]+)

Character Class[a-z0-9_?=-]+

+matches at least one character from the set below:

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

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

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

?the literal ? (63₁₀ / 77₈ / 3F₁₆)

=the literal = (61₁₀ / 75₈ / 3D₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

$end of line

Global pattern flags

i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

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

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

^.+(video\/|\/watch\?v=|embed\/)([a-z0-9_?=-]+)$

New

http://www.youtube.com/video/ZNvzVScj8ws
https://www.youtube.com/watch?v=ZNvzVScj8ws
http://www.youtube-nocookie.com/embed/ZNvzVScj8ws