You have three genuinely free options and they do different jobs.
Lichess, for a strong second opinion on one game
Lichess gives every free account deep Stockfish 19 server analysis of 40 games a day, the same allowance Patrons get, plus an analysis board that runs Stockfish in your browser with no limit at all. You can import a game you played somewhere else. Checked on lichess.org/features, 9 September 2026.
If you want to know what you should have played on move 23, this is the fastest free answer there is.
Stockfish on your own machine, for full control
Stockfish is free and open source. Downloaded and pointed at a PGN file it will analyze as deeply as you have patience for. It is the most powerful option and the least convenient, and it tells you nothing about which of your mistakes repeat.
Blunderbase, for the mistakes that keep coming back
An engine tells you about one move in one game. It does not notice that the same mistake has now cost you several games, because it never looks across games.
Blunderbase imports your completed Rapid and Blitz games from Chess.com or Lichess, finds the moments that cost you the most, labels the pattern where it can prove one, and gives those positions back as practice scheduled at 1, 3, 7, 14 and 30 days.
The free plan is $0. It covers the last ninety days of your games, review of every move, personal puzzles, scheduled practice and progress tracking. The engine’s reading of every position is unmetered, and it runs on your own device rather than on a server, which is why it costs nothing to give away.
The analysis itself is not capped. The full split between the plans is on the pricing page.
Should I analyze my games with or without Stockfish?
With. This is not a close call. An engine is right about evaluation in a way that no human coach and no language model is, and there is no version of self-review that beats knowing the truth about the position.
What an engine cannot do is tell you why you played the move, or which of your errors is a habit. That is what you add on top of the engine, not what you swap it for.
Blunderbase takes the same line internally. Stockfish owns evaluation and the model never grades a move. Any figure the written explanation cites has to already exist in the report it was shown.
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