A simple, exam‑style code judge built with Flutter and a native C backend to help students practice and validate their programming logic.
- Native C backend: code evaluation • compilation • output comparison
- Flutter (Dart): UI • theming • localization • navigation
- Purpose & Benefits
- Features
- Installation & Support
- Contribution-Guidelines
- Contact
- Legal & Privacy
- Screenshots
CodeJudge is designed to help computer science students practice and prepare for their programming exams. It combines a modern Flutter UI with a high‑performance native C backend to simulate real exam conditions — without syntax highlighting, auto‑completion, or other IDE helpers. While it might help you to improve your skills, there is no guarantee that it will improve your skills or grades. All your code is stored locally on your device—your data remains private and is never shared by this app.
- 10+ interesting exercises for your preparation
- Exercises of varying difficulty
- Training mode without any helpers
- Fast and deterministic evaluation powered by a native C backend
- Basic error messages by the backend
- 8 supported languages: C, Go, Python, C++, Rust, Ruby, JavaScript, PHP
- Light & dark mode support
- Material You‑inspired design
- English & German translation
- Responsive UI for all screen sizes
In order to use this app you need to install it and you need to make sure the compiler and interpreter by the programming languages you want to use is installed. You don't need to install e.g. a compiler for C if you don't want to use C, but you need to have a compiler for e.g. Go installed if you use Go. If the compiler misses, the C backend returns the error "No compiler found (Code -2)".
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Make sure the compilers/interpreters for the languages you want to use are installed.
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Download the .zip or .tar.xz file from the latest Release
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Extract the archive
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Now you can move the folder wherever you want to keep this app
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Open the file CodeJudge.desktop in a text editor and adjust the following lines:
Exec=PATH/TO/THE/UNZIPED/RELEASE/CodeJudge
Icon=PATH/TO/THE/UNZIPED/RELEASE/app_icon.png
Replace PATH/TO/THE/UNZIPED/RELEASE/ with the actual folder path where you placed the app.
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Move the edited CodeJudge.desktop file to the following folder:
~/.local/share/applications
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Make the .desktop file executable by running this CMD command:
chmod +x ~/.local/share/applications/CodeJudge.desktop -
You can now launch CodeJudge from your application menu.
You don't need to install all compilers and all interpreters, because they are just called when you select the programming languge in the training mode. It's allways possible to use the other languages too, by installing their compilers.
Everyone is welcome to participate in and adapt this project. All contributions and usage are governed by the Apache 2.0 License. Please see also CONTRIBUTING.md for guidelines.
Clone the repository:
git clone https://github.com/naibaf-1/CodeJudge.gitCodeJudge consists of two tightly integrated components:
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Flutter Frontend (Dart)
- User interface
- Training mode
- Localization & theming
- Exercises
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Native C Backend
- Compiles and executes user code
- Compares output with expected results
- Returns deterministic responses
/lib— Flutter UI (Dart)/native— CodeJudge engine (C)
Please note that this project adheres to a Code of Conduct.
By participating, you are expected to uphold this code.
If you fork and redistribute CodeJudge, please include the following attribution in your documentation:
Based on CodeJudge by Fabian Roland (naibaf-1)
You can contact me through GitHub—open an issue or submit a pull request.
This project is licensed under the Apache License 2.0. Please respect my NOTICE.md as well.
For details regarding data usage, third-party content, and security practices, please refer to this README.
This document is intended to provide full transparency for users and complies with the requirements of the Apache License 2.0 and relevant privacy standards.
If this app is distributed via an app store, the store description may refer to this README for further information.
This app uses icons from the Material Icons Library by Google, licensed under the Apache License 2.0. © Google. Licensed under the Apache License, Version 2.0.
This app stores the code entered by the user locally on the device to process the user’s code and compare it with the solution. CodeJudge performs all evaluation locally on your device. No code is uploaded or transmitted to any server. All stored data is anonymous and used solely for functionality within the app.
This app generates a file containing the code entered by the user. This file is necessary for the whole backend and it's overwritten as soon as the user enters code using the same programming language. While no personal data is collected or transmitted, users should be aware that unencrypted data may be accessible to other apps on the same device. To mitigate this risk, we recommend using devices with secure storage and keeping your system up to date. All data remains local and anonymous.
This app was developed to help computer science students preparing for their exams written on paper or at least without helpers like syntax highlighting. This means that CodeJudge intentionally provides no helpers such as syntax highlighting or auto‑completion. Since this app depends on good exercises, feel free to add or improve exercises!
 See all exercises |
 See details |
|---|---|
 Train your skills |
 See hints |
 Toggle the settings |