Stockfish 18
On Android it runs on the phone with its neural evaluation. It marks your blunders, draws the evaluation graph and finds the move you missed.
AI chess coach app
You lost that one for a reason. Here it is.
Play a game, here in your browser or in the app, then find out what actually went wrong. The engine does the calculating, and your coach turns it into a sentence you can use in the next game.
Better on your phone? Google Play · App Store — no ads
Free to start · iPhone, iPad, Android · No ads
- 20rivals, from beginner to grandmaster
- 493lessons in five courses
- 100essential endgames to learn and practise
- On-deviceengine: analysis works offline
Top ten for targeted training and for playing and practice in ChessPivot’s comparison of 150 chess improvement services. Read the review
After the game
The game ends. That’s when it starts to teach.
Three steps, and the last one is the one no engine gives you.
Play a game
Against one of twenty rivals, or bring your own in from Lichess or any PGN.
The engine reads it
Accuracy for both players, the graph of the game and every move graded, from best to blunder.
Your coach explains it
The idea you missed and what to play instead, in plain words and written for your rating.
Why another chess app
Engines are free. Understanding isn’t.
Any phone runs an engine stronger than any human alive. It shows you the move and a number. It never tells you what you walked into, and a number is not a lesson. Chess Coach keeps the engine and adds the part that was missing.
“We’re entering the endgame. King activity matters more than material now: walk him to the centre before you push anything.” An actual comment, from an actual game review
- Plain words, for your rating. The same mistake is explained differently at 900 and at 1900.
- The engine decides, the coach explains. The AI never invents the evaluation: it puts into words what the engine found.
- Your choice of AI. Use credits inside the app, or your own key with OpenAI, DeepSeek, Gemini, Claude or Qwen.
Practice Lab
A game has three parts. So does the training.
One lab for each phase of the game, with the same shape: learn the idea, then play it out against an opponent that punishes you for getting it wrong. And a fourth for the skill all three depend on.
I · The opening
Your repertoire, until it sticks
Pick the openings you actually play. The trainer drills them with spaced repetition and tells you when a line is due. Then you play the same line against Maia, trained on real club games, so it goes wrong the way people do.
Spaced repetition
Played out against Maia
Italian Game · free
How the opening trainer works
II · The middlegame
The plan when the book runs out
Move fifteen, the theory is over and nobody told you what comes next. The Middlegame Lab goes by pawn structure: the Carlsbad, the Benoni, the French chain and twenty-two more, each with the plan for both sides and a game to play from the diagram.
25 pawn structures
1,000 positions from real games
d5 in the Sicilian · free
The 25 pawn structures
III · The endgame
The hundred endgames you have to know
The goal, the technique in four lines, and then you play it against an engine at full strength that will not slip. Some you have to win, some you only have to hold. Guided mode warns you the moment a move throws the result away.
100 endgames, 5 families
45,000+ positions to practise
King and pawn basics · free
The 100 essential endgames
In all three · Calculation
See it at a glance, not after ten minutes
Every game comes down to a position where you have to work out the move. Train it two ways: decisions you read, calculate and play out, and the Woodpecker method, the same set in seven cycles until you see the answer without thinking.
149 decisions by theme
2 Woodpecker sets of 150
First 10 of each set · free
The Woodpecker method, explained
The four labs are part of Premium. Free to try: the Italian Game, the d5 square in the Sicilian, the king and pawn basics, and the first ten positions of each calculation set.
Courses
If you’d rather be told where to start
Five guided courses, 493 lessons that mix theory, puzzles, endgames, openings and games against bots. The first one teaches the rules from scratch and is free.
- 1First StepsHow the pieces move, checkmate, a first plan29 lessons · free
- 2BeginnerTactics and openings · 0–100044 lessons
- 3IntermediateStrategy and endgames · 1000–180094 lessons
- 4AdvancedCalculation and plans · 1500–2100139 lessons
- 5MasterOpenings and technique · 1900+187 lessons
Play
Somebody to play, whatever mood you’re in
Twenty rivals with faces and ratings, from a beginner who hangs pieces to a grandmaster who doesn’t. Five levels, four opponents each, and they make the mistakes their rating makes.
HU ChessOnline games with a clock, a rating and a monthly ranking.
PuzzlesA daily one, by theme, a streak to keep alive and a three-minute storm.
Analysis boardSet up any position, get the engine lines and ask the coach what it means.
Under the hood
One engine can’t do all three jobs
Judging a position, playing like a person and fitting inside an iPhone are different problems. They all run on your device, not on a server, so analysis works with no signal.
Caissa
iOS doesn’t let an app start a separate process, and Stockfish’s licence would cover the whole app if it lived inside. Caissa does the same job under a licence that lets it, on the device just the same.
Maia
Not a strong engine turned down: a network trained on real games by players of each strength, so it plays the move a club player would actually pick. It is the rival in the Opening Lab.
Below about 1300 the official Stockfish can’t be made weaker, so the beginner rivals run on Fairy-Stockfish, which can: a bot labelled 800 loses the way an 800 loses, not by throwing a piece at random. The engines are GPL and their sources are published: open source notice.
How the coach is powered
Bring your own key, or don’t think about it
The engine runs on your phone. The explanations come from a language model, and you choose how to pay for it.
Buy and forget
One credit is one explanation from the coach. Premium comes with 150 welcome credits, and credit packs don’t expire.
Pay the provider at cost
Paste an API key and the app talks to that provider directly. A full game review typically costs a fraction of a cent.
Nothing to sell
Keys are encrypted on the device and only leave it to reach the provider you chose. No ads, and nobody’s games are sold.
Guides
Go deeper, one topic at a time
Chess game analysisFind out what went wrong in your games, in plain words.
Learn chess from scratchFive courses, from the rules to master level.
Chess puzzlesFree tactics in your browser, with a rating that adapts to you.
Chess bots by levelTwenty rivals, from beginner to grandmaster.
Opening trainerYour repertoire with spaced repetition, then played for real.
Pawn structuresThe 25 that decide the middlegame.
Essential endgamesThe 100 to know, and a way to practise them.
How to calculateA method for finding the move, and two ways to train it.
The Woodpecker methodThe same set, faster every cycle, until you see it at a glance.
Your next game
Take your coach with you
Start free on iPhone, iPad or Android. No ads, and no subscription needed to play, analyse or take the first course.
Sign in and your games, ratings and progress follow you to the other device.