Regex Tester

Test regular expressions and inspect match groups

//gi

Test String

Loading editor…

Match Details0 matches

No matches found in the test string

Regex Tester Online

How to use Regex Tester

Enter your regular expression pattern in the Regex field.
Add any flags (e.g. g, i, m) in the Flags field.
Paste your test text into the Test String panel.
Matches are highlighted automatically, and the exact matches list is displayed.

Edge Cases & Limitations

Invalid regex syntax will show a detailed syntax error.
Catastrophic backtracking might cause browser lag with complex patterns on large strings.

Keyboard Shortcuts

Ctrl/Cmd + K — Open Command Palette to switch tools instantly.

100% Client-Side Privacy

All inputs are processed entirely inside your browser's memory using JavaScript. No data is ever transmitted to any server. Your tokens, JSON payloads, cURL commands, and timestamps never leave your machine.