Updated September 28, 2026. Short version: only what the board needs, never sold.
Without signing in, levels are saved only in your browser's local storage. They never reach the server unless you sign in and choose to import them.
Page visits are counted with Vercel Web Analytics, which does not use cookies or track you across sites. It records things like the page, the referring site and your country, so I can see which posts bring people in.
Nobody else. Your board is private to your account and there are no public profiles. Nothing is sold or shared for advertising. The data lives with the services that run the site: Vercel (hosting) and Neon (database). Syncing sends your Marvel Rivals UID to MarvelRivalsAPI.com to look up playtime.
Unlinking your Marvel Rivals account removes your synced playtime and keeps your levels. Deleting your account removes everything above right away. You can also revoke the board's access in Discord under User Settings, Authorized Apps.
Sign in on the board to see the delete option for your account.
Proficiency Board is a free fan project by Pablo Padilla, not affiliated with NetEase Games or Marvel. Questions and requests go to the project's GitHub page.