C Compiler Online

The fastest online C compiler with 100% browser-based compilation.

Write, compile, and run C code instantly. Powered by Clang/LLVM compiled to WebAssembly. Your code never leaves your browser.

Files

main.c

Console

PressCtrl+Enteror click Run to execute code

1.1M+

Developers

23M+

Projects Created

2016

Since

TRUSTED BY *

* registered email accounts from associated companies

The Most Powerful Online C Compiler

PlayCode's C compiler is trusted by developers worldwide for learning, prototyping, and competitive programming. Write, compile, and run C code instantly in your browser with zero setup, no installation, and no waiting. Whether you're learning C, practicing algorithms, or building systems software, our online C compiler provides everything you need.

Unlike traditional online C compilers that run code on remote servers, PlayCode runs C entirely in your browser using WebAssembly. This means your code stays private, compilation is instant, and you can even work offline after the initial load.

What is a C Compiler?

A C compiler translates your human-readable C source code into machine code that computers can execute. The compilation process involves preprocessing, parsing, optimization, and code generation. PlayCode's online C compiler uses Clang/LLVM, one of the most advanced compiler toolchains available, compiled to WebAssembly for browser execution.

This means you get the same powerful compiler used by professional developers, running directly in your browser. No configuration, no virtual environments, no makefiles. Just write C and run it.

For C++ projects with classes and templates, try our C++ Compiler or explore our Python Compiler for scripting.

Write C with Full Standard Library

PlayCode includes the complete C standard library. Use all the standard headers you need for real C development, from basic I/O to complex data manipulation.

Input/Output

stdio.h for printf, scanf, file operations, and formatted I/O.

Memory & Utilities

stdlib.h for malloc, free, qsort, atoi, and memory management.

Strings & Math

string.h, math.h for string operations and mathematical functions.

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

int main() {
   // Dynamic memory allocation
   int *arr = (int*)malloc(5 * sizeof(int));
   printf("Memory allocated!\\n");
   free(arr);
   return0;
 }

100% Browser-Based Compilation

PlayCode's C compiler runs entirely in your browser using WebAssembly technology. When you click Run, your code is compiled locally by Clang/LLVM (compiled to WASM), then executed using a WASI runtime. No server is involved.

This architecture provides significant advantages: your code never leaves your device (100% privacy), there are no rate limits or quotas, compilation is instant without network latency, and the compiler works offline after the initial load.

🔒

Complete Privacy

Your code is never uploaded to any server. Everything runs locally.

⚡

Zero Latency

No network round-trips means instant compilation every time.

Multi-File C Projects

Unlike simple online C compilers that only support single files, PlayCode lets you create real C projects with multiple source files and headers. Organize your code properly with .c source files and .h header files.

Use the file tree to create new files and folders. Include your headers with #include "myheader.h" and the compiler will find them automatically. Your entire project structure is preserved and auto-saved in your browser.

// main.c
#include<stdio.h>
#include"utils.h"// Your custom header

int main() {
   print_array(numbers, 5);
   return0;
 }

Use Cases for Online C Compilers

Learning C Programming

Perfect for beginners learning C without installing GCC or Clang. Practice pointers, memory management, and data structures. See your code run instantly and learn from compiler errors.

Competitive Programming

Practice coding problems with instant feedback. Test your algorithms quickly without IDE overhead. Perfect for preparing for coding interviews and programming contests.

Algorithm Practice

Implement sorting algorithms, linked lists, trees, and graphs. Test edge cases quickly. The console shows execution time so you can measure performance.

Teaching & Education

Share C code examples with students via simple URLs. No software installation required. Perfect for classrooms, online courses, and tutorials.

Quick Testing

Test C snippets and validate logic before adding to larger projects. Debug individual functions in isolation. No project setup needed.

Why Choose PlayCode's C Compiler?

⚡

Instant Compilation

No server round-trips. Code compiles locally in your browser via WebAssembly.

🔒

100% Private

Your code never leaves your browser. No server storage.

📁

Multi-File Support

Create real projects with .c and .h files organized in folders.

🌐

Works Offline

After initial load, compile and run C code without internet.

🚀

No Rate Limits

Compile as many times as you want. No quotas, no waiting.

📱

Works Everywhere

Desktop, tablet, phone - any device with a modern browser.

How to Use Our C Compiler

Write C Code Instantly. No setup, no installation required. Open your browser and start writing C code immediately. The full C standard library is included and ready to use.

C17 Ready

Full standard library included: stdio.h, stdlib.h, string.h, math.h, and more. Start coding immediately with no configuration.

Compile and Run Instantly. Our C compiler executes your code instantly in your browser using WebAssembly. No server round-trips, no waiting. Press Ctrl+Enter and see results immediately.

Debug with Powerful Console. See compiler errors and program output in the console panel. Clear error messages help you fix bugs quickly. View execution time for performance testing.

Create Multi-File Projects. Organize your C code like a real project. Create header files (.h) for declarations and source files (.c) for implementations. Include your custom headers with #include "myheader.h".

Project Structure

📁my-project/

📄main.c

📄utils.h

📄utils.c

📄math_helpers.h

Include Your Headers

// main.c
#include<stdio.h>
#include"utils.h"
#include"math_helpers.h"

intmain() {
   print_greeting();
   return0;
 }

📁Create folders and files

🔗Automatic #include resolution

💾Auto-saved in browser

Share Your Code. Open your project in the full editor and share it with others. Your code is saved in the cloud and accessible from any device. Get a unique URL to share with colleagues or students.

.playcode.io

Features

Code Autocomplete. Enhance your coding speed and efficiency with smart code autocomplete feature. Avoid checking the documentation frequently.

Bug Finder. PlayCode can identify and display all errors, providing assistance to fix them. Write, run code, correct any errors quickly.

The Most Flexible Layout.

Arrange panels as you like.

Upload Assets. Images, videos, sounds, shaders and others.

Color Themes.

Feels great in any environment.

Ready to use
JavaScript Playground

No need to configure your own IDE preset, start immediately.

Start coding

Code seamlessly from any device

Jumping from your Mac to your iPad to your iPhone is no problem. Web editor is optimized for all devices.

Frequently Asked Questions

What is a C compiler?

A C compiler translates your C source code into machine code that can be executed by your computer. PlayCode's online C compiler uses Clang/LLVM compiled to WebAssembly, running entirely in your browser. This means instant compilation with no server round-trips, complete privacy, and offline capability.

Is PlayCode's C compiler free?

Yes, PlayCode's C compiler is completely free to use. You can write, compile, and run unlimited C code without paying anything. There are no rate limits or compilation quotas. Pro features like AI assistance and private projects are available for subscribers.

What C standard does PlayCode support?

PlayCode supports modern C standards including C17 (C18) via the Clang compiler. You get access to all standard C features including designated initializers, compound literals, variable-length arrays, and the complete C standard library.

Can I use the standard C library?

Yes! PlayCode includes the full C standard library. You can use stdio.h for input/output, stdlib.h for memory allocation and utilities, string.h for string operations, math.h for mathematical functions, and all other standard headers.

Does the C compiler work offline?

Yes, PlayCode works offline after the initial load. The Clang compiler runs entirely in your browser using WebAssembly, so you can keep coding without an internet connection. Your code is saved locally and syncs when you're back online.

How fast is the online C compiler?

PlayCode's C compiler is optimized for speed. After the initial load of the Clang toolchain (about 100MB cached), compilation is near-instant because everything runs locally in your browser. There's no server round-trip, making it faster than traditional online C compilers.

Can I create multi-file C projects?

Yes! PlayCode supports multi-file C projects. Create multiple .c and .h files using the file tree. Organize your code with header files for declarations and source files for implementations, just like a real C project.

How does browser-based C compilation work?

PlayCode uses browsercc, which compiles Clang/LLVM to WebAssembly. When you click Run, your C code is compiled locally in your browser to WebAssembly, then executed using a WASI runtime. This provides native-like performance without any server involvement.

Is my code private?

Absolutely. Your code never leaves your browser. Unlike server-based compilers that send your code to remote servers, PlayCode's C compiler runs 100% client-side. Your code stays on your device, providing complete privacy and security.

What our users value

Easy to use

Fast

Best for learners

Best online C compiler

I've tried many online C compilers, but PlayCode is the only one that runs entirely in my browser. No server delays, no rate limits, just instant compilation. Perfect for practicing algorithms and data structures.

- Michael Chen, Systems Programmer