#1 alex@example.com
8 - 24
- Group 1
alex - Group 2
example.com - name
alex - domain
example.com
Regex testing runs locally in your browser. Nothing is uploaded.
Regex Tester
Enter a pattern, choose JavaScript regex flags, highlight matches, inspect capture groups, and preview replacement output.
Regex testing runs locally in your browser. Nothing is uploaded.
Test a regular expression
Contact alex@example.com and sam@example.com for details.
Matches
2 matches
#1
#2 sam@example.com
29 - 44
- Group 1
sam - Group 2
example.com - name
sam - domain
example.com
A local regex tester for quick debugging
Use this regex tester for log snippets, validation patterns, search expressions, extraction rules, named groups, and replacement templates while you iterate on JavaScript regular expressions.
Patterns are compiled and tested in your browser with native RegExp behavior. Invalid patterns show inline errors, and your test string is never sent to a server.
How to use this tool
-
Enter a regex pattern
Type the pattern without surrounding slashes, then select any JavaScript flags you need.
-
Paste test text
Add the text you want to search and review highlighted matches plus capture groups.
-
Preview replacements
Optionally enter a replacement template using $1 or named group syntax to see the output live.
FAQ
Does this regex tester upload my text?
No. Regex testing runs locally in your browser.
Which regex engine does it use?
It uses the JavaScript RegExp engine built into your browser.
Does it support capture groups?
Yes. The match list shows indexed groups and named groups when your browser reports them.
Can a bad regex freeze the page?
Pathological regular expressions can make the current browser tab slow, but they do not affect a server because everything runs locally.