Privacy policy

Last updated: August 13, 2026

The short version

CSS Breakpoint Button collects no data. No analytics, no telemetry, no tracking, no accounts, and no network requests to any server. Nothing you do leaves your browser.

What the extension stores

Your settings (which sites have the badge enabled, the selected rule set per site, any custom rule sets you create, and the badge position) are saved with your browser's built-in extension storage (storage.sync). If you're signed into your browser, the browser itself may sync those settings across your devices; that sync is operated by your browser vendor under its own privacy policy, not by us. We never see it.

Why it asks for permissions

• Access to sites you visit: the badge is rendered by a small script that runs on the page to measure the viewport and display the current breakpoint. It reads nothing else and sends nothing anywhere.
• Storage: to save the settings described above.
• Active tab: so the popup can show the live breakpoint readout for the tab you're looking at.

What the extension publishes on the page

On sites where you've enabled the badge, the extension writes the current breakpoint state into the page (as data-cbb-* attributes and a window.__cssBreakpoint global) so that your own tools can read it (see the docs). This is derived from the viewport size and your chosen rule set only, stays inside the page, and is removed when you disable the badge.

Changes

If this policy ever changes, the change will be visible in the open-source repository and on this page.

Contact

Questions? Open an issue on GitHub.