Is SimpleLogin by Proton: Secure Email Aliases safe?

SimpleLogin by Proton lets any page trigger alias creation and read the generated alias from its email input.

The extension injects a SimpleLogin button beside email fields on HTTP and HTTPS pages. A page can trigger that button, causing the extension to send the page URL's hostname to SimpleLogin and write the returned alias into the page-owned input where the page can read it.

Part of this rating comes from analysis signals we haven't published as detailed findings yet.