Regular Expressions 101

Pro

^start of line

Group 1(https?:\/\/)

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)

Character Class[\w.-]+

+matches at least one character from the set below:

\wany word character

.the literal . (46₁₀ / 56₈ / 2E₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Negative Lookbehind(?<!\.domain\.edu)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

domainthe literal text domain (case sensitive)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

eduthe literal text edu (case sensitive)

$end of line

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

^(https?:\/\/)[\w.-]+(?<!\.domain\.edu)$

https://www.google.com
http://not.the.best.example.org
http://another.bad.example.erewhon.edu
https://my.domain.com
https://your.page.domain.edu
http://good.domain.edu

Substitution

\1my.domain.edu

https://www.google.com
http://not.the.best.example.org
http://another.bad.example.erewhon.edu
https://my.domain.com
https://your.page.domain.edu
http://good.domain.edu