Privacy
Privacy
Short version: your patterns, test text and replacements stay in your browser. RegexQuill has no accounts, no cookies, no ads and no trackers.
What happens to what you type
Parsing, matching, replacing, explaining, drawing diagrams, escaping and ReDoS checks all run in your browser, partly in Web Workers, which are background threads of the same page. None of it is sent to RegexQuill or anyone else. The pages make no network requests with your input.
Share links
The Share button copies a link that holds the pattern, flags and, on the tester and the replace page, the test text and replacement, in the part of the address after #. Browsers do not send that part to the server when the link is opened. When a page reads a shared pattern from the address, it removes it from the address bar straight away. Anyone you give a share link to can read what it contains, so do not share links holding text you want to keep private.
What is stored on your device
- Your colour theme choice (light, dark or system), in this browser’s local storage under
regexquill-theme.
Nothing else is stored. Files you download (replace results, diagrams) are created in your browser and saved by it.
Analytics
The site uses Cloudflare Web Analytics, which counts page views without cookies or cross-site tracking and never receives what you type, paste or drop into the tools.
Hosting
The pages are static files served by Cloudflare. There is no RegexQuill back end, database or log of the patterns you test. Fonts and scripts are served from this site; no third-party font or script CDNs are used.
Links
Links to other sites, including the sister sites in the footer, CleanTempMail and WebTraceCheck, are ordinary links. Those sites have their own privacy policies.
Last updated 28 October 2026.