Regexlab
BundlApps
Test regex with live highlights
Screenshots
Included in your subscription
Get Regexlab and 78+ other apps for $9.99/month.
About this app
Regexlab is a forensic-grade pattern inspector for ECMAScript regex. Type a pattern and the corpus lights up in real time — full matches highlighted, capture groups marked with stacked underline strokes by depth, every token decomposed token-by-token in plain English. Toggle flags as chips, switch to replace mode to preview $1/$2 substitutions, and pull from a curated library of starter samples (email, URL, IPv4, phone, ISO date, hex, semver, markdown link).
Key features
- Live match highlighting as you type pattern or text
- Token-by-token plain-English breakdown of your pattern
- Capture group inspector with stacked underline rendering by depth
- Replace mode with $1, $2 backreference preview
- Printed-card cheat sheet — anchors, classes, quantifiers, lookarounds
- Quick samples — email, URL, IPv4, phone, ISO date, hex color, semver
- Save and load test corpora (.regexlab.json) and copy match list as JSON or CSV
Ratings & reviews
Regexlab is exactly what I was looking for. Lightweight, fast, and does the job without unnecessary bloat. Highly recommend.
Been using Regexlab daily for a few weeks now. The interface is clean and intuitive. Great addition to the BundlApps catalog.
Switched to Regexlab from a paid alternative and honestly prefer it. Runs locally, no account needed, just works.
What's new
Bug fixes and performance improvements.
Additional information
How to get Regexlab
Install BundlApps
Download the free installer for Windows. Takes under a minute.
Find Regexlab
Search the catalog or browse Developer apps. Click to install instantly.
Start using it
Runs locally, no account needed inside the app. Your files stay on your machine.