I recently built CForge, a free online C and C++ compiler that runs
entirely in the browser. No signup. No ads. No installation.
Try it here: https://v0-online-c-complier.vercel.app
Why I built it
Most online C compilers either have too many ads, require an account,
or don't support basic things like stdin input or command line arguments.
I wanted something clean and fast.
How it works
The browser doesn't know how to compile C code. So here's what
actually happens when you click Run:
- Your code is sent to a proxy API route
- That route forwards it to Piston – an open source code execution engine running GCC 10.2
- The output comes back in under a second and displays in the browser
That's it. No Docker on your machine. No backend you have to manage.
What it supports
- C and C++ (GCC 10.2)
- Standard input (scanf, cin)
- Command line arguments (argc, argv)
- Separate stdout, stderr and compile error display
- Shareable links – your code is encoded in the URL
- Auto-saves to localStorage so you don't lose work on refresh
Tech stack
- Next.js
- CodeMirror 6 (editor)
- Piston API (code execution)
- Vercel (hosting)
What's next
- Error line highlighting (click a compile error, jump to that line)
- More language support
- Dark/light theme toggle
Would love feedback from the community – especially C learners who
use online compilers regularly.
