About CompilerOnline
Our Purpose
CompilerOnline was founded in 2026 as a free developer tool designed to remove friction from programming. Whether you are learning a new language, testing a code snippet, checking an algorithm, or debugging complex async logic, CompilerOnline provides a clean developer workspace directly in your browser without requiring any local installations, terminal configs, or environment variables.
The Technology Stack
To ensure a high-fidelity development environment, CompilerOnline couples a premium web client with isolated backend sandboxes:
- Interactive Frontend: We integrate Microsoft's monaco-editor library (the same code editor powering VS Code) to provide syntax highlighting, bracket matching, indentation rules, and smart autocompletion presets.
- Dockerized Sandbox Runtimes: When you click "Run Code", your script is sent to our backend. The API launches a stateless, isolated, disposable Alpine Linux Docker container. The script is compiled and executed inside the container, standard output streams are captured, and the container is immediately destroyed.
- Stateless Sharing: Clicking "Save" persists your code snippet anonymously to our SQLite database and generates a unique routing slug, allowing you to share workspaces with colleagues, students, or interviewers.
Compiler Specifications & Limits
To keep the platform stable, safe, and fair for all users, all compilation requests are strictly bound by the following resources:
| Configuration | Sandbox Limit | Purpose |
|---|---|---|
| Execution Timeout | 5.0 seconds maximum | Prevents runaway scripts and infinite loops from consuming CPU cycles. |
| Memory Limit | 100 MB (200MB C# & React) | Protects the host OS against memory leaks and buffer allocation exploits. |
| Sandbox Isolation | Docker Container (Read-Only FS) | Guarantees that filesystem changes are destroyed after the run finishes. |
| Network Access | Disabled (isolated loopback) | Blocks containers from launching outbound spam, DDoS, or botnets. |
Open Education Initiative
CompilerOnline is built to serve educational communities. Our built-in practice cards, common diagnostics panels, code checklists, and benchmark charts are designed to help programming instructors demonstrate runtime features (like stack memory, pointers dereferencing, and loop structures) visually and interactively.