Privacy policy

Last updated 30 October 2026.

regex.ninja stores what you test on its servers. Do not test passwords, keys or personal data with a Cloud engine.

What is collected

When the server handles a test or a ReDoS check, it records your IP address, the time, the pattern, the flags and the engine and, for a test, the test text.

What stays in your browser

JavaScript and engines you have downloaded run in your browser, marked Local, and their tests are not sent to the server. Two things still reach it:

• The ReDoS check sends your pattern, unless you turn it off.
• Opening or reloading a link that holds a pattern and text sends both, and they may be tested and recorded.

Why

To run the service, fix faults and prevent abuse. Where the GDPR applies, the legal basis is legitimate interests.

Who can see it

Access is restricted to the operator of regex.ninja. This data is not sold, and is shared only with the services below or where the law requires it.

How long it is kept

Up to 30 days.

Other services

• Cloudflare carries all traffic to this site. See its privacy policy.
• Google Fonts serves this site's fonts, so your browser connects to Google. See its privacy policy.

Stored in your browser

Your browser keeps your settings and any engines you download. Clearing this site's data removes them.

Your rights

Depending on where you live, you may have the right to see or delete your data, to object to its use, and to complain to a data protection authority.