Privacy Policy
Last updated September 1, 2026
StockFishy is a browser extension that analyzes chess positions on Chess.com and Lichess.org. This page explains what data we collect, why, and how it's used.
The short version
The chess analysis itself — reading the board and calculating moves — happens entirely on your own device. Nothing about the positions you analyze, the games you play, or your engine results is ever sent to our servers. The only data we collect is what's needed to run your account and enforce your plan's daily usage limit.
What we collect
- Account info. When you sign in with Google, we receive your email address and basic profile info from Google, via our authentication provider (Supabase). This identifies your account and lets you access it across devices.
- Usage counts. We record how many positions you've analyzed each day, tied to your account, solely to enforce your plan's daily limit (e.g. 50/day on the free plan). We do not record which positions, which games, or which sites you analyzed them on.
- Billing info, if you subscribe. Payment is handled entirely by Stripe — we never see or store your card details. We store only your Stripe customer/subscription IDs, used to know which plan you're on.
What we never collect
- The contents of chess positions you analyze, or any part of your games.
- Your Chess.com or Lichess account details, username, or activity.
- Browsing history outside of Chess.com and Lichess.org, where the extension is active.
Third parties we use
- Google — for sign-in (OAuth). Google's own privacy policy applies to that sign-in step.
- Supabase — hosts our database and authentication. Your account info and usage counts are stored there.
- Stripe — handles all payment processing for paid plans. Stripe's own privacy policy applies to any payment info you provide them directly.
We do not sell your data, show ads, or share your information with anyone beyond these providers, which exist solely to run the product.
Data deletion
You can request deletion of your account and all associated data at any time by contacting us below.