Chrome extension · chess.com + Lichess

Your coach, right where you already play.

A side panel that reads your last 20 games, finds the mistake you keep making, and explains the why in plain words — right next to your board on chess.com or Lichess.

Get your game breakdown How it works ↓

Free diagnosis from your nickname. No PGN copy-paste. The engine runs on your device.

YOUR MOVE — you play White

legal-trap.fen r2qkbnr/ppp2ppp/2np4/4N3/2B1P3/2N5/PPPP1PPP/R1BbK2R w KQkq · white to move · you play White

chesscoach · watching your game
[engine] +M2 for White coach> Black just played Bxd1 — your queen is gone. Feels like a disaster, but the engine says +M2: you have a forced mate. Find it.

The engine tells you what. The coach makes you find it — and explains why. Free retries, no timer.

tap a glowing piece to move
Live demo of the coaching loop: Légal’s trap, the moment after 5…Bxd1. The engine says what (+M2) — you find the moves on the board, the coach explains why. You play White.
The problem

The engine says +2.4. It never says why.

Evaluation bars don’t teach

You lost, you open the analysis, the bar says you were better on move 19. Better how? What was the plan, what was the threat, what should you look for next time? The number never answers. You close the tab none the wiser.

?? ?? your rating · 3 months

Your mistakes repeat — and nobody connects them

The blunder you made tonight is a cousin of the one from last Tuesday. Game-by-game review treats each as a one-off. Until someone reads your games as a series, the same trap keeps collecting your rating points.

Random puzzles don’t fix your blunders

Puzzle number forty-one thousand whatever is a fine tactic — for somebody. If your real leak is hanging pieces after long thinks, solving random pins at random ratings is cardio for a broken arm.

How it works

From nickname to diagnosis in three moves

01

Type your nickname

chess.com or Lichess. The extension fetches your public games right in your browser — no account, no upload, no PGN ritual.

02

Get your diagnosis

A local Stockfish digs through your last 20 games. The AI coach turns the raw analysis into a named list of your actual weaknesses — and explains each one in plain words.

03

Train, then play coached

Drills rebuilt from your own blunders, puzzles aimed at your leaks, opening advice for your level — and the coach in the side panel whenever you sit down to play.

Why it’s different

Every analysis site makes you come to it

ChessCoach works where you play.

No “export your PGN, open our website, paste it here”. The coach is a side panel on chess.com and Lichess — it’s already there when the game ends, and still there when the next one starts.

Explains why, not just what

Plans, threats, and your habits — in words. Engine lines are there if you want them, but they’re the footnote, not the lesson.

Trains on your blunders

Your worst moments become your exercise set. Positions from your own games, replayed until the pattern sticks.

282,000 puzzles, aimed

Not random tactics — puzzles selected to match your weak motifs and your rating, from a 282,000-puzzle base.

Opening stats for your level

What scores at 1200 is not what scores at 2400. The coach reads your repertoire against players like you, not against grandmaster theory.

Local engine. Private by design

Stockfish runs in your browser. Your games are analysed on your device and never uploaded — only your questions to the coach leave it.

The core stays free

Diagnosis from your nickname, local analysis, and a daily portion of training are free forever. Pro lifts the limits; it never walls off the core.

See it in action

What the coach actually shows you

Not screenshots of a website you’d have to visit — these are the surfaces that appear right next to your board.

Move quality, explained

Italian, move 8

coach> Ng5?! goes for f7 too early — Black plays d5 and you’re the one defending. d3 first keeps the bishop’s aim. The engine’s best here is the quiet move.

Trained on YOUR blunders

from your game · May 14
Bc4?? — a free piece → ...d5, ...dxc4

coach> You keep leaving the bishop on c4 — ...d5 hits it and it walks off for a pawn. We drill until you spot ...d5 before it lands.

Openings at your level

Sicilian · ~1200 pool

What scores at 2400 isn’t what scores at 1200. The coach reads your repertoire against players like you.

Your rating, projected

if the leak gets fixed

*Illustrative. The lift comes from closing one repeating leak — not from grinding random puzzles.

Pricing

One coach. Three ways to keep him.

Free

$0 forever

  • Diagnosis of your last 20 games
  • Coach chat to try, then a daily taste
  • Puzzles from the 282k base
  • Local Stockfish analysis, unlimited
Get your game breakdown

No card, no account — a nickname is enough.

Most useful

Pro

$9.99 / month

  • Everything in Free
  • Unlimited coach chat while you play
  • Full training on your own blunders
  • Opening analytics for your level
  • Fresh diagnosis whenever you ask
Get your game breakdown

Cancel any time. The free core stays free.

Lifetime

Personal

$100 once

  • Everything in Pro — own it forever
  • Bring any AI model with your own key
  • No subscription, ever
  • Set up personally, by email
Get it now — by email

Fulfilled by email, person to person. Available before the store launch.

282,000

puzzles in the training base

20

of your games read for every diagnosis

0

games uploaded — the engine runs on your device

FAQ

Fair questions

Do my games leave my device?

No. Stockfish runs inside your browser, and your games are fetched from the chess.com / Lichess public APIs straight to your machine. The only thing that leaves your device is what you ask the coach — the current position and your question go to our proxy to generate the answer, and we don’t store them. Details in the privacy policy.

Does it work on Lichess?

Yes. The side panel lives on both chess.com and lichess.org, with the same diagnosis, training and coach.

I’m rated 800. Is this for me?

Especially for you. The coach explains ideas in plain words instead of engine lines, the 282k puzzle base spans every level, and opening advice is tuned to what actually scores at your rating. Strong players get depth; beginners get a translator.

Which AI model answers me?

By default, a frontier-grade model served through our backend — you don’t configure anything. On the Personal plan you can plug in your own key for any major provider and the panel will use your model instead.

What stays free?

The core: the diagnosis from your nickname, local engine analysis, and a daily portion of training. Pro removes the limits; it never walls off what Free already gave you.

When can I install it?

The extension is in final hardening and lands on the Chrome Web Store in June 2026. Leave your email and you’ll get exactly one message — on launch day.

One move left

Sit down. He’s already read your games.

Type a nickname, get a diagnosis, and meet the first coach who shows up at your board instead of asking you to come to his.

Free game breakdown

Leave your nickname and email — we’ll read your recent games and send you a breakdown: the mistakes you keep making and how to fix them.

No spam. Privacy.