GitHub Pixel Diff collects nothing. It has no analytics, no telemetry, no crash reporting, and no server of its own. Nothing about you or the pages you visit is sent anywhere.

What it stores

Settings, and only settings: the comparison threshold, whether the outline around changes is drawn, which frame was shown last, and whether the before/after/diff switcher is visible. They are kept by the browser's own extension storage. If you are signed into Firefox and have extension sync turned on, the browser may sync them across your devices; that is the browser's mechanism, not ours.

No image, file name, repository name, URL, or account information is stored.

What it accesses

The extension runs on one address: https://viewscreen.githubusercontent.com/diff/img, the frame GitHub uses to display image diffs. Inside that frame it reads the two images GitHub has already loaded and compares them in your browser. It does not run on github.com pages, does not read your repositories, and does not touch any other site.

The comparison happens entirely on your machine. The images never leave it.

Third parties

None. No data is shared, sold, or transferred to anyone, and no code is loaded from a remote server — everything the extension runs ships inside the package.

Contact: https://github.com/Nemo-Illusionist/gh-pixel-diff/issues