Regex Cheatsheet & Tester

Reference table of regex syntax with an inline live tester.

A printable-style reference for regex anchors, character classes, quantifiers, groups, alternation, lookarounds and flags — paired with a live tester that highlights matches as you type. Great as a learning aid or a quick reminder.

Common use cases

Look up an unfamiliar regex token without leaving the page
Test a one-liner pattern alongside the syntax reference
Onboard a teammate to regex with a single self-contained page
Review JavaScript regex flags before debugging a tricky match

Frequently asked questions

Which regex flavour does it cover?▾

JavaScript regex (the same engine your browser uses). Most syntax overlaps with Python, Java and Go regex but lookbehinds, named groups and \p{...} have minor differences.

Can it explain a regex?▾

Not yet — for full expression breakdowns try a tool like regex101. The cheatsheet helps you read individual tokens.

Are flags listed?▾

Yes — gimsuy in the Flags section, with a short description of each.