Last updated: September 2026.

Regexer is built so the thing you interact with — your pattern, flags and test string — never reaches us. This policy covers everything the site does touch.

What you type stays on your device

The matcher, the replace preview, the explain mode and the backtracking check all run in JavaScript inside your browser. Patterns you write, text you paste and replacements you preview are never transmitted to us or to any third party — there is no API, no sharing feature, no “save” button to leak through. You can verify this directly: open your browser’s network inspector while you use the tool, or load the page and disconnect — it keeps working.

Server logs

This site is hosted on Cloudflare. When your browser requests a page, Cloudflare processes standard request metadata — IP address, user agent, timestamp, requested URL — to deliver the page, protect against abuse and measure aggregate traffic. We don’t combine these logs with identity information, because we don’t have any: no accounts, no sign-ups, no forms that store data.

Advertising and cookies

If advertising is enabled on this site, it is served by third-party networks such as Google AdSense. Ad networks may set cookies or use similar identifiers to measure impressions and — where permitted — personalize ads. You can opt out of personalized advertising through Google’s Ads Settings or with a browser that blocks third-party cookies. Every feature of the tester works identically whether or not ads load.

Analytics

We may use privacy-respecting, aggregate analytics (no cross-site tracking, no personal profiles) to see which pages are used most. The contents of the tool’s input fields — your pattern and test string — are never included in any analytics or telemetry event.

Your choices

• The articles on this site are fully readable with JavaScript disabled; only the interactive tester needs it.
• Blocking third-party scripts stops ads and analytics without affecting the tester — all tool logic is served from this site’s own files.
• Questions about this policy: hello@nxtolerance.com.