Stop guessing what “+2.8” means.
Stockfish gives you a number and a move list. ChessTold gives you the reason in one plain sentence, checked against the position. It runs on your own computer, on games you have finished.
Engine output and ChessTold sentence, side by side
- Move
- Nc7+
- To move
- White
- FEN before
- r3kb1r/pp3ppp/8/1N6/8/8/PPP2PPP/R1B1K2R w KQkq - 0 1
Stockfish 19, depth 14
+6.8 Nc7+ Kd7 Nxa8 Bc5 O-O Rxa8
Correct, but it doesn’t say why.
ChessTold
Nc7+ is a knight fork: it checks the king on e8 and attacks the rook on a8 at the same time. No black piece can capture the knight. The king must move. After Kd7, White takes the rook with Nxa8 and ends up ahead in material.
From engine line to sentence
- 01
Read the game
The web review replays your PGN move by move. The extension will read the move list of the Lichess or Chess.com board you already have open.
chess.js · every move replayed and checked legal
- 02
Run Stockfish on your computer
The single-thread Stockfish 19 build runs in a Web Worker in your browser. There is no server and nothing is uploaded.
1.8 MB WASM · depth 14 · median 27 ms, worst 91 ms per position (Chrome, Apple-silicon laptop)
- 03
Find the idea
Detectors look for forks, pins, skewers, discovered attacks, trapped and undefended pieces, mates, outposts, open files and passed pawns. A tactic only counts if the engine’s own line actually wins the material.
20 hand-checked positions must pass before a release
- 04
Say it, or say nothing
A template turns the confirmed idea into one sentence. When no simple idea explains a move, ChessTold says so instead of guessing.
“No simple tactic or positional idea explains e4.”
Pay once. No subscription, no expiring credits.
The browser extension explains moves on the Lichess or Chess.com board you already have open. It is on its way to the Chrome Web Store and Firefox Add-ons. The web review on this site is free today.
Free
$0
- Web review on this site: every game, every move
- Extension: mistakes (?!, ?, ??) explained in 2 games a day; each analysis board you open counts as one
Pro
$12.99 once
- Every move explained, in every game, with no daily limit
- “Why is this quiet move best?” positional explanations
- Weakness report: your most common mistakes across your finished games
Finished games and analysis boards only. Chess.com and Lichess ban engine help during play, including correspondence and Daily games still in progress. ChessTold switches itself off on those pages.
How it compares
Checked 17 October 2026. Prices change; follow the links.
| Product | Plain-English explanations | Where it runs | Price |
|---|---|---|---|
| ChessTold | Yes. Template sentences, each confirmed against the engine’s own line | Your browser. Extension on your Lichess / Chess.com board (in development) | Web review free. Pro $12.99 once (planned) |
| DecodeChesssource | Yes. AI explanations of moves and plans | DecodeChess website | Free: 1 game a day. $8.25 a month or $84 a year. Credit packs $15 (60) or $25 (120), valid 12 months |
| Chess.com Game Reviewsource | Coach explanations on every move with Diamond only | Chess.com | Free: 1 review a day. Unlimited from Platinum. Prices vary by country |
| Lichesssource | No. Engine lines and “Learn from your mistakes” | Lichess | Free. Browser analysis unlimited, server analysis 40 games a day |