Full policy: https://webdevelopertools.dev/privacy

Web Developer Tools processes everything on your device. Page data the tools read (DOM, CSS, cookies, headers, storage, console output) is displayed locally and never transmitted. No analytics, telemetry, tracking or ads.

The extension contacts webdevelopertools.dev only on your explicit action: (1) optional Pro sign-in, which returns your account email and plan to the extension; (2) the feedback form, which sends the message you typed and an optional email address. Both are declared as optional data collection and Firefox asks for your consent before either happens. Nothing is sold or shared with third parties.