Online C Compiler

Write, run, and share code snippets — no setup required.

main.c

Alice
30

Output

Click Run to see the output here.

#include <stdio.h>

int main(void) {
    char name[64];
    int age;
    scanf("%63s", name);
    scanf("%d", &age);
    printf("Hello, %s! You are %d years old.\n", name, age);
    return 0;
}

Compile and run C online in your browser

A free online C playground and compiler. Write C in your browser, hit Run, and gcc compiles and executes your program in seconds. No local gcc, no clang, no make or CMake to set up first.

The editor is built on the same engine as VS Code, so C syntax highlighting, autocompletion, and diagnostic squiggles all work. Code compiles with gcc on Alpine Linux against musl libc, with the full C99/C11 standard library available — <stdio.h>, <stdlib.h>, <string.h>, <math.h>, <time.h>, <stdint.h>. Good for debugging a segfault, testing a bit-manipulation trick, or prepping for a C interview.

What makes this C playground useful

Instant C compilation — write code, press Run, and see output from the online gcc compiler in seconds, no Makefile or CMake needed.
Full C syntax highlighting, header autocompletion, and clear gcc diagnostics, powered by the same editor engine as VS Code.
Stdin input is supported. scanf, getchar, fgets(buf, n, stdin) all read from the playground's input box, so interactive and interview-style programs run without scaffolding a project. No gcc, clang, MinGW, or WSL on your end.
gcc compiler on Alpine Linux — write C with pointers, structs, and the full C99/C11 standard library, then compile and run in one click.

What you can build in the C playground

Pointer arithmetic, arrays, and string manipulation: core C idioms you can step through with printf debugging.
Data structures by hand — linked lists, binary trees, hash tables — plus classic algorithms (sorting, BFS, DFS, recursion) the way C exposes memory layout.
Quick C experiments: test a format specifier, check a struct's sizeof, verify a bitmask, or confirm how an operator associates without spinning up a Makefile.

Online C compiler FAQ

Is the online C compiler free?

Yes, the online C playground is free to use. No sign-up, no gcc to install, and no MinGW or WSL to configure — open the page and compile.

Do I need gcc or a C compiler installed?

No install needed. You don't need gcc, clang, MinGW, or WSL on your machine. The online C compiler compiles your code with gcc on Alpine Linux and runs it in seconds.

Does the C playground work on mobile and Chromebooks?

Yes. The C playground runs in any modern browser, on desktop, tablet or mobile. Good for compiling C from a Chromebook, iPad, or school computer where you can't install a toolchain.

Does the online C compiler support scanf and stdin?

Yes. scanf, getchar, and fgets(buf, n, stdin) all read your typed lines the same way they would when you run ./a.out locally and type at the terminal. Pointers and memory tricks that might segfault also run safely, since the binary executes in a sandboxed Alpine container.

How do I learn C after trying the playground?

Edit the sample C code, press Run, and iterate. When you want something more structured, Coddy's interactive C course covers pointers, memory management, structs, and the standard library with hands-on exercises.