Regex Tester
Test regular expressions against sample text. Highlight matches, inspect groups, and toggle flags.
How to use Regex Tester
- 1Enter a pattern
Type your regex pattern and toggle flags (g, i, m, s, u).
- 2Add test text
Paste the text you want to match against.
- 3Inspect matches
All matches highlight in the text. Capture groups list below.
Frequently asked questions
Which regex flavor is this?+
JavaScript (ECMAScript) — the regex engine built into your browser.
Does it handle very large inputs?+
Up to a few MB comfortably. Pathological regexes (catastrophic backtracking) may hang the page — refresh to recover.
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