Regex Tester
Test regular expressions with live matches.
//gi
2 matches
Reach us at ada@4devs.app or support@sitefluence.com anytime.
| # | Match | Index | Groups |
|---|---|---|---|
| 1 | ada@4devs.app | 12 | — |
| 2 | support@sitefluence.com | 29 | — |
About the Regex Tester
Test a JavaScript regular expression against sample text and see every match as you type, with its position and capture groups, including named groups. Invalid patterns report their error inline instead of failing silently. This uses your browser's own regex engine, so behaviour matches what your JavaScript will actually do at runtime.
How to use the Regex Tester
- Enter your pattern, without the surrounding slashes.
- Set flags such as i for case-insensitive or m for multiline.
- Paste the text to test against.
- Review the match list, each with its index and captured groups.
Frequently asked questions
- Which regex flavour is this?
- JavaScript (ECMAScript), running in your browser's engine. Patterns that rely on PCRE or Python features such as lookbehind variants or possessive quantifiers may behave differently.
- Do I need the g flag?
- No. The tester always collects every match, so you can leave g off and still see all of them.
- Are named capture groups supported?
- Yes. Use (?<name>...) and the named groups appear alongside the numbered ones for each match.
- Why does my pattern show an error?
- The pattern or flag string is not valid JavaScript regex. Common causes are an unescaped forward slash, an unbalanced bracket, or a flag letter that does not exist.