# Chessr

> Chessr is a chess training browser extension for game review, analysis boards, opening study, and practice against the engine — no setup required.

## What is Chessr

Chessr is a browser extension that acts as your personal chess coach. It connects to powerful server-side engines to review your finished games, analyze positions on the analysis board, and help you understand why certain moves are strong.

Chessr uses two best-in-class engines running on its servers — **Komodo** for human-like training lines, and **Stockfish** for deep game analysis. All computation happens server-side, meaning zero performance impact on the user's device.

Engine suggestions run on analysis boards and in games against the computer.

## Key Features

- **Dual-Engine Architecture**: Komodo for human-like training lines + Stockfish for deep analysis — all running server-side with zero load on your device
- **Analysis Board**: Evaluation bar and move arrows drawn on the analysis board
- **Game Review**: Accuracy, effective Elo and every move classified for each finished game
- **12,000+ Openings**: Opening study with alerts showing where a line leaves known theory
- **8 Playing Personalities**: Engine, Aggressive, Defensive, Active, Positional, Endgame, Beginner, and Human — each changes how the engine plays
- **ELO Range 300-3500**: From beginner to master level, the engine adapts to your level
- **Bot Practice**: Train against the computer with engine hints
- **Armageddon Mode**: Premium feature for high-stakes practice under pressure

## Why Komodo + Stockfish

Chessr is the only chess extension that combines two engines for different purposes:

- **Komodo** is widely regarded as the best engine for producing human-like moves. Rather than always finding the absolute best computer move, Komodo suggests moves that a strong human player would actually play — making it ideal for learning and improving naturally.
- **Stockfish** is the strongest chess engine in the world, used for deep position analysis and game review where maximum accuracy matters.

Both engines run on Chessr's servers, so the extension stays lightweight and fast regardless of the user's hardware.

## Pricing

- **Free**: Game reviews, analysis board with evaluation bar, 2 personalities, 8 openings, ELO up to 2000
- **Premium**: €3.99/month, or €34.99/year — all 8 personalities, full ELO range 300-3500, 12,000+ openings with deviation detection, Armageddon mode
- **Lifetime**: €79.99 one-time payment — all premium features forever
- 3-day free trial on Premium, no credit card required
- 14-day money-back guarantee on all paid plans

## FAQ

### What is Chessr and how does it work?
Chessr is a browser extension that uses server-side engines (Komodo and Stockfish) for game review, analysis boards, opening study and practice against the computer.

### What devices are supported?
Chrome and other Chromium browsers on desktop, plus mobile-compatible browsers.

### What ELO levels does Chessr support?
Free users: ELO 300-2000. Premium users: full 300-3500 range. The engine adapts to your level.

### What are the 8 Personalities?
Engine (minimal errors), Aggressive (attacks and Queen play), Defensive (king safety), Active (open positions), Positional (solid maneuvering), Endgame (pawn promotion focus), Beginner (basic play), Human (plays like strong humans).

### Is Chessr free?
Yes. The free tier includes game reviews, an analysis board with evaluation bar, 2 personalities, 8 openings, and ELO up to 2000. Premium unlocks all features.

### Does Chessr include an opening repertoire?
Premium includes 12,000+ openings for study. When a line leaves known theory, Chessr shows where it deviated and the best response.

## Blog — Detailed Guides

For in-depth chess improvement content, see our blog:

- [Best Chess Analysis Software in 2026: Complete Guide](https://chessr.io/blog/best-chess-analysis-software-2026): Compare desktop engines, online platforms, and browser extensions for chess analysis.
- [How to Improve Your Chess Rating Fast: 7 Proven Strategies](https://chessr.io/blog/how-to-improve-chess-rating-fast): Opening preparation, game review, endgame mastery, and more.
- [Building Your Chess Opening Repertoire: A Beginner's Guide](https://chessr.io/blog/chess-opening-repertoire-guide-beginners): Best openings for White and Black, study methods, and deviation detection.
- [Understanding Chess Playing Styles: From Aggressive to Positional](https://chessr.io/blog/chess-personalities-playing-styles): Explore the 8 playing personalities and find your style.
- [Chessr vs Lichess: Honest Comparison 2026](https://chessr.io/blog/chessr-vs-lichess-comparison): Honest comparison — what each tool does best and how they work together.
- [Chessr vs Chess.com: Honest Comparison 2026](https://chessr.io/blog/chessr-vs-chess-com-comparison): Chess.com is the world's largest platform. Chessr adds engine-powered training alongside it.
- [Chessr vs ChessBase: Modern Cloud Coaching vs Desktop Software](https://chessr.io/blog/chessr-vs-chessbase-comparison): Cloud-native coaching vs professional desktop software — cost, features, and who each is for.
- [Chess Training Plan: From 300 to 1000 ELO in 90 Days](https://chessr.io/blog/chess-beginner-training-plan-300-1000): Structured week-by-week plan for beginners — blunder elimination, tactics, opening principles, endgames.

## Links

- Homepage: https://chessr.io
- Download: https://download.chessr.io
- Blog: https://chessr.io/blog
- Discord Community: https://discord.gg/72j4dUadTu
- Roadmap: https://roadmap.chessr.io