Regular Expressions 101

^start of line

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

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Positive Lookahead(?=[^\s.]+\.[^\s.]+\.[^\s.]+$)

Negated Character Class[^\s.]+

+matches at least one character outside the set below:

\sany whitespace character

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Negated Character Class[^\s.]+

+matches at least one character outside the set below:

\sany whitespace character

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Negated Character Class[^\s.]+

+matches at least one character outside the set below:

\sany whitespace character

.the literal . (46₁₀ / 56₈ / 2E₁₆)

$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

^\S+?\.(?=[^\s.]+\.[^\s.]+\.[^\s.]+$)

New

web1.com
test.web2.com
www.test.web3.com

web1.com
test.web2.com
www.test.web3.com