Prepare opponents
Search players, inspect their games and understand recurring opening choices before you sit down at the board.
Offline chess database · Mobile study tool
A complete chess database in your pocket.
Explore real games, prepare opponents, study positions, build repertoires and share diagrams — directly from your phone.
OfflineDownload once, study anywhere.
Real gamesProfessional, correspondence and club collections.
No accountYour work stays on your device.
Player searchFind games fast
Opening studyReal positions
Designed for practical study
From a question to real games in seconds.
Study positions
Start from a position and navigate to real games where similar structures and ideas appeared.
Build your work
Create repertoires, save lines, copy FENs and export diagrams for notes, training or preparation.
How to use ChessCodex
Watch the main workflows.
Short mobile demos show how ChessCodex works in practice: search, preparation, diagram recognition, databases, positions and repertoires. Videos are muted and optimized for phone screens.
01
Search a player and open a game
Launch ChessCodex, find a player, open their games and start studying directly on the board.
02
Prepare an opponent
Search a player, inspect their games and generate a practical opening preparation before your next match.
03
Recognize clean digital diagrams
Import synthetic chess diagrams and turn them into editable board positions in seconds.
Designed for clean digital diagrams. Photos from books, magazines or real boards are not officially supported yet.
04
Explore a position
Reach a position and find real games connected to it.
05
Filter databases
Choose the collections you need and focus your search.
06
Keep databases offline
Install the chess database packs you need and keep them on your device.
07
Edit positions
Create or adjust positions easily so you can analyze them.
08
Copy FEN and share diagrams
Export positions for notes, training, messages or preparation.
09
Build repertoire lines
Create repertoires, rename them, add multiple opening lines and let ChessCodex organize related variations automatically. You can also share your repertoires with friends.
Real chess databases
Built around large offline collections.
ChessCodex is designed for serious database work on mobile. Install database packs, explore them offline and switch between collections according to your study goal.
Professional games
High-level games for opening study, preparation and model-game research.
Correspondence games
Deep theoretical games and long-form opening exploration.
Club games
Practical games below elite level for realistic preparation and patterns.
Local first
No ChessCodex account required.
Download the databases once and study offline. Your personal notes, repertoires and games stay on your device.
- Offline database access after download
- Local notes and personal work
- Clear database coverage inside the app
- Future database updates may be offered separately
FAQ
Quick answers.
Does ChessCodex work offline?
Yes. Once databases are downloaded, they can be used without an internet connection.
Why is ChessCodex offline-first?
ChessCodex is offline-first for two reasons: privacy and reliability. Your study material, notes and personal games stay on your device, and you can prepare, search and study even when you do not have an internet connection.
Do I need an account?
No. ChessCodex is designed to work without a ChessCodex account.
Are my personal notes uploaded?
No. Your personal work stays on your device.
Which databases are included?
The app shows available databases and their coverage directly inside the database/download screen.
Will databases be updated?
Each database clearly shows its coverage period. Future database updates may be offered separately.
Will ChessCodex be updated?
Yes, if the app is well received, we definitely plan to keep improving it. Future updates may include bug fixes, usability improvements, new features and database-related enhancements.
Can I import my own games?
Yes. ChessCodex can import your own games. Importing up to a few thousand games should not be a problem on most devices. Personal game databases currently use lighter indexing than the main ChessCodex databases, but this is an area we may improve in future versions.
Can ChessCodex recognize diagrams from photos?
ChessCodex is designed to recognize clean digital or synthetic chess diagrams. Photos from books, magazines or real boards are not officially supported yet.
Is there a PC version of ChessCodex?
Not yet. ChessCodex is currently a mobile app. If there is enough interest, a desktop version is a natural next step.
Can I suggest a feature?
Yes. Feature suggestions are welcome. You can send ideas, feedback or bug reports using the support email listed on this page.
Why is ChessCodex a paid app?
ChessCodex is the result of many months of development work involving several people. Building and maintaining the app, distributing large databases, updating content and keeping the experience reliable all have real costs. We tried to keep the price as low as possible while still making the project sustainable.