Privacy

Last updated 12 November 2026

Your pattern and your text stay in the tab. Here is the whole of it.

What the page collects

Nothing. There is no analytics script, no advertising tag, no cookie, no session and no account. The page is a set of static files: HTML, one stylesheet, two JavaScript files and self-hosted fonts. Matching, replacing and code generation are functions that run on what is already in the page.

Where your pattern and text go

Nowhere. The pattern, the flags and the sample text are read from the form, used in memory and never written anywhere else. There is no request in the page at all, and a content security policy blocks every other origin, so there is no address they could be sent to.

Closing the tab discards everything, including a pattern you were in the middle of writing. Nothing is saved as a draft.

What is stored in your browser

Two settings, kept in local storage so the page opens the way you left it: pikkola.regex.theme (light or dark) and pikkola.regex.lang (en, ko or ja). Neither contains a pattern or a piece of the text. To clear them, open your browser's site data settings for regex.pikkola.com and delete the entry, or use a private window.

Clipboard

A Copy button writes to the clipboard through the browser's own permission, and only when you press it. The page never reads the clipboard on its own.

What the host sees

Cloudflare serves these files, and like any hosting provider it records requests to the site in its own logs: an IP address, a user agent, the file requested, the time. That record is about the page, not about the pattern, because the pattern never travels. We do not add analytics on top of it and we do not read those logs.

If you write to us

Mail to [email protected] arrives in a mailbox a person reads. We keep it while the conversation is useful and use it only to answer. We do not add the address to a list.

Changes

If this page ever changes in a way that matters, the date at the top changes with it. There is no newsletter to announce it to, so the date is the record.

Contact

Questions about any of this: [email protected].