Interactive•Client-Side Processing
Regex Tester
Test JavaScript regular expressions with named groups, replacement output, and a worker timeout.
Developer workbench
⌘ / Ctrl + Enter to runConfigure. Run. Inspect.
JavaScript regex engine, isolated in a worker with a two-second timeout and a 1,000-match cap.
30 input bytes
Output
How to Use Regex Tester
01
Enter a pattern without slash delimiters and select flags.
02
Paste test text and optionally set a replacement.
03
Run the expression in the isolated worker.
04
Inspect matches, indexes, groups, and replacement output.
Frequently Asked Questions
What flags are supported?
Standard JavaScript regex flags are supported: g (global), i (case-insensitive), m (multiline), and s (dotAll).
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