Free Regex Tester Online

No account · No subscription · No usage cap · Full features — 100% free forever

A fully featured online regex tester with live match highlighting, named groups, replace mode, split mode, token explainer, and 12 quick patterns — completely free, with no account, no rate limit, and no server costs because everything runs in your browser.

All features, no account required.

Open the Free Regex Tester →

Everything included at no cost

Live match highlighting
All 6 flags (g, i, m, s, u, d)
Named capture groups
Lookahead & lookbehind
Replace mode with preview
Split mode
Token-by-token explainer
12 quick patterns
Export as JSON / CSV
Shareable permalink
Unlimited test runs
No login required

Why is it free?

Because the regex engine runs entirely in your browser using the built-in JavaScript RegExp object, there is no server processing cost. The tool is a static HTML file with a small JavaScript file — it has no backend, no database, and no compute cost per request. That's why it can be free without limits.

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