正規表現テスター
ライブハイライト機能付きの無料正規表現テスター。JavaScript正規表現を入力すると、入力中に一致とキャプチャグループが更新されます。ブラウザで使用されているのと同じエンジンです。
Runs in your browserUpdated Apr 26, 2026
Pattern
//
Test String
2 matches
Highlighted
Email ada@example.com or grace@test.io for info.
よくある質問
›Which regex flavor is used?
JavaScript regex (ECMAScript), evaluated by the same engine your browser uses. Matches PCRE for most common patterns but differs on lookbehinds and named groups.
›What flags can I use?
g (global), i (case-insensitive), m (multiline), s (dotAll), u (unicode), y (sticky).
›Are matches highlighted live?
Yes — every keystroke re-runs the regex and updates highlights immediately.
›Are capture groups shown?
Yes. Numbered and named capture groups are listed for each match.
›Is my input sent anywhere?
No — everything runs in your browser. Useful when testing regex against sensitive text.
›Is the regex tester free?
Yes — fully free, no signup.