Regex Tester
Test JavaScript regular expressions and inspect match positions locally.
Inputs stay on your device; no account required.
JavaScript syntax; flags g, i, m, s, u. Up to 1,000 pattern characters, 50,000 text characters and 500 matches. Runs in an isolated worker with a 1.5-second time limit. No replacement operation.
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About this tool
Test JavaScript regular expressions and inspect match positions locally. JavaScript syntax; flags g, i, m, s, u. Up to 1,000 pattern characters, 50,000 text characters and 500 matches. Runs in an isolated worker with a 1.5-second time limit. No replacement operation.
How to use
- Enter the JavaScript regular expression, flags and sample text separately.
- Run the test and inspect each match, position and captured group.
Example
Pattern \d+ with flag g on item 12 and item 34 finds 12 and 34.
Frequently asked questions
Which regular expression syntax is supported?
JavaScript syntax; flags g, i, m, s, u. Up to 1,000 pattern characters, 50,000 text characters and 500 matches. Runs in an isolated worker with a 1.5-second time limit. No replacement operation.
Do I need an account?
No. This free tool can be used without creating an account.
Where is my input processed?
This tool processes its input in your browser. Tool input is not uploaded for processing. General site usage statistics are separate; see the privacy policy.