Regex Tester
Test JavaScript regular expressions against your text with live match highlighting, capture groups and flags. Client-side only.
How it works
- 1
Paste your input
Type or paste your data into Regex Tester.
- 2
Adjust options
Tweak the available settings — the output updates as you type.
- 3
Copy the result
Copy the output to your clipboard or download it as a file.
Common uses
- Test a pattern against sample text with live match highlighting.
- Debug a capture group before using it in code.
- Try flags (g/i/m/s/u) on a tricky expression.
About the Regex Tester
Test JavaScript regular expressions against your text with live match highlighting, capture groups and flags. Client-side only.
Regex Tester is part of a free, privacy-first toolkit. Everything is computed instantly on the client, so your data never leaves the page — useful when you're working with sensitive payloads.
Because regex tester works without any sign-up or installation, you can use it as often as you like and it's always available — on desktop or mobile, and even offline.
Explore more developer tools, or try JSON Formatter · JSON Validator.
Related tools
Related guides
Regex Tester — FAQ
JavaScript's RegExp engine, with the standard g, i, m, s and u flags toggleable as you test.