Regular Expressions 101

Pro

^start of line

.*any character (except for line terminators), repeated any number of times

Group 1(youtu.be\/|v\/|u\/\w\/|embed\/|watch\?v=|\&v=)

1st Alternativeyoutu.be\/

yoututhe literal text youtu (case sensitive)

.any character (except for line terminators)

bethe literal text be (case sensitive)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

2nd Alternativev\/

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

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

3rd Alternativeu\/\w\/

uthe literal u (117₁₀ / 165₈ / 75₁₆) (case sensitive)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

\wany word character

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

4th Alternativeembed\/

embedthe literal text embed (case sensitive)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

5th Alternativewatch\?v=

watchthe literal text watch (case sensitive)

\?the literal ? (63₁₀ / 77₈ / 3F₁₆)

v=the literal text v= (case sensitive)

6th Alternative\&v=

\&the literal & (38₁₀ / 46₈ / 26₁₆)

v=the literal text v= (case sensitive)

Group 2([^#\&\?]*)

Negated Character Class[^#\&\?]*

*matches any number of characters outside the set below:

#the literal # (35₁₀ / 43₈ / 23₁₆)

\&the literal & (38₁₀ / 46₈ / 26₁₆)

\?the literal ? (63₁₀ / 77₈ / 3F₁₆)

Non-Capturing Group(?:(\?t|&start)=(\d+))?

?repeats the group contents below at most once:

Group 3(\?t|&start)

1st Alternative\?t

\?the literal ? (63₁₀ / 77₈ / 3F₁₆)

tthe literal t (116₁₀ / 164₈ / 74₁₆) (case sensitive)

2nd Alternative&start

&startthe literal text &start (case sensitive)

=the literal = (61₁₀ / 75₈ / 3D₁₆)

Group 4(\d+)

\d+a digit, repeated at least once

.*any character (except for line terminators), repeated any number of times

Global pattern flags

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

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

Detailed match information will be displayed here automatically.

25 tokens

Regular Expression

^.*(youtu.be\/|v\/|u\/\w\/|embed\/|watch\?v=|\&v=)([^#\&\?]*)(?:(\?t|&start)=(\d+))?.*

New

http://youtu.be/xxxxxxxx?t=30s

https://www.youtube.com/watch?v=xxxxxxxx&start=30

Substitution

http://youtu.be/xxxxxxxx?t=30s

https://www.youtube.com/watch?v=xxxxxxxx&start=30