Proton’s autofill currently works only in the web and mobile apps, which leaves Windows users having to copy-paste or manually type sensitive data into desktop programs. This not only wastes time but also increases the risk of typos and accidental exposure. Competitors such as Bitwarden and 1Password already provide native Windows autofill extensions, leaving Proton at a usability disadvantage on the desktop.

To address this, we propose a lightweight, system-wide autofill extension for Windows — a secure background plugin that uses the Windows clipboard and input APIs to detect form fields and fill them automatically. All data would remain encrypted on Proton’s servers, and the plugin would decrypt each value only momentarily to insert it into the corresponding field before securely wiping it from memory. This preserves Proton’s zero-access architecture and ensures that no sensitive data persists locally.

Users could enable or disable autofill per application, maintaining granular control over where credentials can be used. The feature would support common field types such as logins, payment details, addresses, and custom entries. By integrating with the existing Proton Vault API and leveraging the Windows Credential Provider framework, the system can offer a native experience without compromising Proton’s strict security principles.

The benefits include faster workflows through the elimination of manual entry, reduced exposure to keyloggers or clipboard attacks, a unified experience across all platforms, and competitive parity with other leading password-management solutions. Making the component open source would further reinforce transparency and allow community auditing and contributions.

We hope the Proton team will consider prioritizing this feature to significantly enhance the desktop experience for Windows users while upholding Proton’s high security standards.