FREE REGEX TESTER
Free Regex Tester
Enter a pattern and sample text to inspect matches and capture groups instantly.
Your pattern and test text are never uploaded or stored.
- 1Enter pattern
- 2Test in browser
- 3Review results
1 · Enter pattern
Pattern and test text
Enter a JavaScript regular expression without surrounding slashes.
Testing the expression in an isolated browser task.
3 · Review results
Test results
Run the expression to see matches here.
There are many results, so only the first 1,000 were collected.
Highlighted matches
Up to 200 results are highlighted.
Match details
How to use the free regex tester
Test JavaScript regular expressions online for free
Add a pattern, flags, and test text, then inspect ranges and groups.Enter a pattern
Use JavaScript RegExp syntax without surrounding slashes.
Choose flags
Select global, case-insensitive, multiline, or other options you need.
Review matches
Inspect highlighting, positions, capture groups, and download JSON.
REGEX SAFETY
Test expressions without freezing the page
Complex patterns run in a separate Browser Worker and stop at the time limit.
JavaScript syntax
Results follow browser RegExp behavior, which can differ from PCRE, Python, or Java.
750 ms timeout
The isolated task stops before excessive backtracking can freeze the page.
No upload
Patterns and test text stay inside your current browser.
FREE REGEX TESTER FAQ
Regex tester FAQ
Learn about free use, syntax, and privacy.1Is this regex tester free?
Yes. It is free with no usage limit and requires no account.
2Which regex syntax is supported?
It uses JavaScript RegExp supported by your current browser with g, i, m, s, u, and y flags.
3Is my test text uploaded?
No. The pattern and text are processed only on your device, including inside a Browser Worker.
4What happens if a pattern is too complex?
A test that does not finish within 750 ms is stopped automatically while your inputs remain available to edit.