Regex Tester
Regex Tester runs your regular expression against sample text and highlights every match live, with flags and capture-group details.
Last updated: July 2026
Test regular expressions against your text with live match highlighting and capture groups. Free, instant, in-browser regex tester.
Loading tool…
How to use Regex Tester
- Enter a regex pattern and flags.
- Paste your test text.
- See matches highlighted instantly.
Frequently asked questions
Which flavour of regex is this?
JavaScript regular expressions, with support for the g, i, m, s and u flags.
Does it show capture groups?
Yes — it lists matches and their captured groups.
Is my text uploaded?
No, matching runs entirely in your browser.
Related developer tools
UUID Generator
Generate random v4 UUIDs (GUIDs) in bulk and copy them with one click. Free, instant and fully in-browser using the secure crypto API.
Base64 Encode / Decode
Encode text to Base64 or decode Base64 back to text instantly. Free, private, in-browser — supports full Unicode (UTF-8).
JSON Formatter & Validator
Format, beautify, minify and validate JSON instantly. Free, private, in-browser JSON formatter with clear error messages.
QR Code Generator
Generate a QR code from any text, link, email or phone number and download it as a PNG. Free, instant and fully in-browser.