When you upload your Letterboxd export ZIP, the file is processed on our server in memory to read watched.csv. We do not permanently store the ZIP file itself.

We store the list of movies you’ve watched, along with a locally cached poster for each movie (to improve performance and reduce external requests).

Your battle votes are stored and used to calculate Elo ratings and to power personal and future public leaderboards. Votes are associated with an ID stored in your browser cookie and may include your Letterboxd username if present in the ZIP filename. You can clear this by deleting cookies or using the “Log out” option which resets your session.

We also record the time between presenting a pair and your vote (in milliseconds) to help detect spammy activity.

This site uses publicly available endpoints from TMDb/Letterboxd but is not endorsed by them.