Disclaimer

Last updated: October 2026

RegexMate is a regular expression tester: it tests and debugs regular expressions against sample text in real time, visualizing matches, capture groups and a plain-English explanation of the pattern. In practice, it runs your pattern against the sample with backtracking limits so a catastrophic pattern cannot lock the tab, and it highlights each match and capture group with its position so you can see exactly what the engine matched. This page should be read with that tool in mind, because the limits described apply to what it computes.

Everything the tool works with — the pattern and test text you enter — is handled locally. It is usually reached for things like reading someone else's regex line by line, and because nothing is transmitted a visitor can close the tab knowing no copy was made anywhere.

The nature of this site

regexmate.com is an informational site. What RegexMate produces are estimates of a calculation, not measured facts and not professional guidance.

Developer tools

Developer tools produce output you are expected to review. A type generated by RegexMate, a formatted document or a converted value should be checked against your own requirements before it is relied on in production.

External links

External links are offered for reference only. We neither control nor vouch for outside content or its accuracy.

Adverts and sponsorship

The Site is funded by advertising. No advertiser has any say over a result, and no ad should be read as an endorsement.

No warranty

The assumption that matters most for RegexMate is that your input matches the model. It runs your pattern against the sample with backtracking limits so a catastrophic pattern cannot lock the tab, and it highlights each match and capture group with its position so you can see exactly what the engine matched. When it does not — or when rounding, unit handling or browser behavior intervenes — no warranty attaches to the Site, careful as we are with the method.

Before you act on a result

Before you act on any figure from this site, confirm it fits your circumstances. If you spot something wrong, use the contact page — we would rather correct it than defend it.