Pricing
Free, because it runs on your computer
The engine is on your machine, so analysing a game costs nothing to serve — and the analyser is free for good. The small prices below are for the parts that need a server, and for keeping the thing alive.
Free
€0/month
Everything that runs on your own machine.
- Unlimited game analysisStockfish 18, multi-threaded, in your browser.
- Import from chess.comAny public account, a year of games at a time.
- Move grades and accuracyEleven grades, win-probability accuracy, engine lines.
- Custom modePlay your own moves and have them judged against the game.
- Puzzles from your blundersTrained on the positions where you actually lost.
Supporter
€2/month
The price of a coffee, and it remembers your work.
Everything in Free, plus
- An accountYour reviews and puzzle history, kept and synced.
- Picks up on any deviceStart a review on a laptop, finish it on a phone.
- History that survives a cleared browserLocal analyses go when the browser data does. These do not.
Club
€4/month
For the player who reviews in bulk.
Everything in Supporter, plus
- Large batch reviewsHundreds of games mined for what keeps going wrong.
- Opening reportsWhere each line stops working, and what it costs you.
- Progress over timeAccuracy and mistake rate tracked across months.
Prices are per month and shown in euro. Yearly plans are billed once a year.
Why the analysis is free
Most chess sites analyse your games on their hardware, so every review you run costs them processor time and they have to charge for it or sell ads against it. Here the engine is a WebAssembly build of Stockfish that runs in your browser, on your processor. A hundred reviews cost exactly as much to serve as none: the price of the page.
So the free tier is not a trial with the interesting parts removed. It is the whole analyser.
Questions
Will the free tier get worse later? No. Everything that runs locally stays free — that is the whole design, not a promotion.
What am I actually paying for? Storage and sync: an account that keeps your reviews, your puzzle history and your progress across devices, which needs a server that someone has to pay for.
Can I cancel? Yes, any time, and what is already on your machine stays there — your analyses live in your own browser.