The best free regex tester in 2026, no signup, runs in your browser
Regex101 is great until you hit the daily limit, RegExr's UI hasn't shifted in a decade, and most others bury you in ads. Here's a clean, fast, browser-only alternative, plus 12 ready-made patterns including Indian PAN, GSTIN, and credit cards.
Regex testers used to be a solved problem. Then they all monetised. Regex101 caps daily quota for free users. RegExr keeps adding modals. Free debugger tools are ad-soaked. The good news: a regex tester is one of the easiest tools to build in a browser because JavaScript already has a regex engine. There's no reason it should ever touch a server.
What we built
Our regex tester (docs.lovedpdf.com/regex-tester) runs entirely in your browser. Features that matter:
- All 6 flags (g, i, m, s, u, y) with one-line explanations of what each does
- Capture groups + named groups highlighted in the results, so you can see what each group matched
- Live highlighting on the test input as you type
- 12 presets ready to drop in: email, URL, UUID, hex colour, ISO date, IPv4, repeated word, HTML tag, credit card, Indian PAN, Indian GSTIN
- No signup, no quota, no ads
Honest comparison
| Tool | Signup | Quota | Privacy | Best for |
|---|---|---|---|---|
| Regex101 | Optional | Daily limit on free tier | Server-side | Step-by-step debug breakdown (paid) |
| RegExr | Optional | None | Server-side library | Community pattern library |
| iHateRegex | None | None | Server-side | Visual pattern explanations |
| Debuggex | Required for advanced | Trial limit | Server-side | Railroad diagrams |
| LovedDocs | None | None | Browser-only | Fast no-friction testing |
We don't do step-by-step debugging or railroad diagrams. If you need those, Regex101 paid or Debuggex are still ahead. For the 90% case, "does my pattern match the right things?" — browser-only is genuinely faster.
Why "runs in your browser" matters for regex
The strings you paste into a regex tester are usually sensitive: a sample of API responses, a chunk of log output, a customer export you're scrubbing. Uploading them to a third party in order to run a one-line regex against them is exactly the kind of casual data-handling that makes security teams nervous. With browser-only, the data never leaves the tab.
The Indian-context patterns
Most regex testers were built by Western devs and ship Western presets. We added two that come up constantly for Indian developers:
- PAN —
\b[A-Z]{5}\d{4}[A-Z]\b, matches the 10-character PAN format - GSTIN, 15-character format with state code + PAN + entity number + Z + checksum
Try it
- Regex Tester, the tool this post is about
- JWT Decoder, sister tool for inspecting tokens
- URL Encoder/Decoder, for the URL component of a regex match