Regular Expressions 101

^start of line

Negative Lookahead(?!https?:\/\/)

httpthe literal text http (case insensitive)

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

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

\w+a Unicode word character, repeated at least once

Group 1(\.\w+)+

+repeats the group contents below at least once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\w+a Unicode word character, repeated at least once

$end of line

Global pattern flags

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

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.

Search reference

Regular Expression

^(?!https?:\/\/)\w+(\.\w+)+$

New

https://google.com
http://google.com
google.com
subdomain.google.com
google.com/
google