Frequently Asked Questions

Common questions about En Croissant and their answers

General Questions

What is En Croissant?

En Croissant is an open-source, cross-platform chess GUI (Graphical User Interface) designed to be powerful, customizable, and easy to use. It provides a complete toolkit for chess analysis, game management, and training.

Built with modern technologies (Rust and React), En Croissant combines the performance of native applications with a clean, intuitive interface.

What chess engines work with En Croissant?

En Croissant supports all UCI (Universal Chess Interface) engines. This includes popular engines like:

• Stockfish
• Leela Chess Zero (Lc0)
• Dragon
• Komodo
• Any other UCI-compatible engine

The application provides built-in engine management, making it easy to install, configure, and use multiple engines simultaneously for analysis.

En Croissant supports multi-engine analysis, allowing you to compare evaluations from different engines side by side.

Which platforms does En Croissant support?

En Croissant is cross-platform and runs on:

• Windows (7 and later)
• macOS (10.13 High Sierra and later)
• Linux (various distributions)

The application is built with Tauri, ensuring consistent behavior across all platforms with native performance.

How do I import games into En Croissant?

You can import games in several ways:

1. From online platforms: Directly download your games from lichess.org and chess.com using the built-in OAuth integration
2. PGN files: Import standard PGN (Portable Game Notation) files from any source
3. Manual entry: Enter games manually using the board interface

See the Importing Games guide for detailed instructions.

What database formats does En Croissant support?

En Croissant uses SQLite as its primary database format, which provides:

• Fast performance for searching and filtering
• Compact file size with efficient compression
• Full support for position search (both absolute and partial positions)
• Player statistics and tournament data

You can also:

• Import from PGN files
• Export databases back to PGN format
• Merge multiple databases
• Create and manage multiple separate databases

Features & Functionality

Can I analyze games with multiple engines simultaneously?

Yes! En Croissant supports multi-engine analysis, one of its standout features.

You can:

• Run multiple UCI engines at the same time
• Compare evaluations and suggested moves
• Configure each engine with different settings
• See multiple principal variations side by side

This is particularly useful for understanding positions more deeply by seeing how different engines evaluate the same position.

How does repertoire training work?

En Croissant includes a sophisticated repertoire training system with spaced repetition:

• Build your opening repertoire for both White and Black
• Practice your lines with intelligent scheduling based on the spaced repetition algorithm
• Track your performance and identify weak spots
• Get reminded to review positions at optimal intervals

The system helps you memorize your openings effectively by showing you positions just before you’re likely to forget them.

Can I search for specific positions in my database?

Yes, En Croissant supports advanced position search:

• Absolute position search: Find exact position matches
• Partial position search: Search for positions with specific piece patterns, regardless of other pieces

This is powerful for studying specific pawn structures, endgames, or tactical patterns across your entire game database.

Does En Croissant include puzzles?

Yes, En Croissant supports chess puzzle training. You can:

• Import puzzle databases
• Practice tactics with immediate feedback
• Filter puzzles by theme and difficulty
• Track your puzzle rating and progress

See the Puzzles feature page for more information.

Licensing & Privacy

Is En Croissant free and open source?

Yes! En Croissant is completely free and licensed under the GPL-3.0 License.

This means:

• The source code is publicly available on GitHub
• You can use it for free, forever
• You can modify and redistribute it under the same license
• The community can contribute improvements

If you find En Croissant valuable, consider supporting the development through donations.

How is En Croissant different from other chess GUIs?

En Croissant distinguishes itself through:

• Modern technology stack: Built with Rust and React for excellent performance and maintainability
• Cross-platform consistency: Native performance on Windows, macOS, and Linux
• Multi-engine analysis: Compare multiple engines simultaneously
• Integrated cloud sync: Direct import from lichess.org and chess.com
• Spaced repetition training: Advanced repertoire learning system
• Position search: Powerful database search capabilities
• Open source: Transparent development and community contributions
• Modern UI: Clean, intuitive interface with customization options

Does En Croissant collect data or send telemetry?

En Croissant includes optional analytics through PostHog for understanding usage patterns and improving the application.

Your privacy is respected:

• No personal information or game data is collected
• Analytics can be disabled in settings
• All game databases are stored locally on your machine
• OAuth authentication with chess platforms uses secure, standard protocols

The application is open source, so you can verify exactly what data is collected by reviewing the code.

Can I contribute to En Croissant?

Absolutely! Contributions are welcome and appreciated.

Ways to contribute:

• Report bugs and request features on GitHub
• Submit code contributions (see the Contributing Guide)
• Improve documentation
• Help other users on Discord
• Share feedback and suggestions

See the Contributing page for more details.

Technical Questions

What technologies is En Croissant built with?

En Croissant uses a modern technology stack:

Backend (Rust):

• Tauri for the application framework
• SQLite with Diesel ORM for database operations
• Shakmaty for chess logic and position handling
• vampirc-uci for UCI engine communication

Frontend (TypeScript/React):

• React 19 for the UI
• Vite for build tooling
• Mantine for component library
• Chessground for the board visualization
• TanStack Router for routing
• Jotai for state management

This combination provides excellent performance, maintainability, and cross-platform support.

Can I build En Croissant from source?

Yes! Building from source is straightforward:

1. Install prerequisites (Node.js, Rust, pnpm)
2. Clone the repository
3. Run pnpm install
4. Run pnpm build

See the Building from Source guide for detailed instructions and platform-specific requirements.

What is BMI2 compatibility and why does it matter?

BMI2 is a CPU instruction set extension that some chess engines use for faster move generation.

• Modern Intel and AMD processors (2013+) typically support BMI2
• Some engines offer BMI2-optimized builds for better performance
• En Croissant can detect BMI2 support to help you choose the right engine binary

If you have an older processor, use the standard (non-BMI2) engine builds.

Where are my databases and settings stored?

En Croissant stores data in standard application directories:

• Windows: %APPDATA%\en-croissant
• macOS: ~/Library/Application Support/com.encroissant.app
• Linux: ~/.config/en-croissant or $XDG_CONFIG_HOME/en-croissant

Your databases, engine configurations, and application settings are all stored in these locations.

Can’t find what you’re looking for? Check the Troubleshooting page or ask in the community.