Regex Tester & Debugger
Write, test, and debug regular expressions with real-time highlighting. See matches instantly as you type.
How It Works
Enter Your Pattern
Type your regex pattern in the input field. Use the flags dropdown to toggle options like global, case-insensitive, or multiline.
Add Test Text
Paste or type your test string in the editor. Matches are highlighted instantly with a golden background.
Review Matches
See all matches in the sidebar with capture groups. Click any match to jump to its location in the editor.
Regex tester FAQs
Which regex engine does this tester use?
The tool uses the JavaScript regular expression engine built into your browser. Most common tokens, groups, and flags behave like they do in JavaScript, but some advanced features from other flavors (like full PCRE) may not be available.
What do the g, i, m, and s flags do?
The g flag finds all matches instead of just the first, i ignores case, m lets ^ and $ match at line boundaries, and s allows the dot (.) to match newlines. You can toggle these in the flags dropdown above the pattern input.
Is it safe to paste production data here?
While the highlighting runs in your browser, it is still best practice not to paste highly sensitive production logs, personal data, or credentials into any online regex tester. Use anonymized or representative sample text instead.
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