The latest articles on DEV Community by ROHIT Choudhary (@rohit_choudhary_e9c105c75). https://dev.to/rohit_choudhary_e9c105c75 https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F4145476%2Fad06e42c-87ab-465f-83b5-c1e3a774c58e.jpg https://dev.to/rohit_choudhary_e9c105c75 en ROHIT Choudhary Sun, 27 Sep 2026 12:09:04 +0000 https://dev.to/rohit_choudhary_e9c105c75/i-built-a-free-online-c-compiler-from-scratch-heres-how-it-works-3e56 https://dev.to/rohit_choudhary_e9c105c75/i-built-a-free-online-c-compiler-from-scratch-heres-how-it-works-3e56 <p>I recently built CForge, a free online C and C++ compiler that runs <br> entirely in the browser. No signup. No ads. No installation.</p> <p><strong>Try it here:</strong> <a href="https://v0-online-c-complier.vercel.app" rel="noopener noreferrer">https://v0-online-c-complier.vercel.app</a></p> <h2> Why I built it </h2> <p>Most online C compilers either have too many ads, require an account, <br> or don't support basic things like stdin input or command line arguments.<br> I wanted something clean and fast.</p> <h2> How it works </h2> <p>The browser doesn't know how to compile C code. So here's what <br> actually happens when you click Run:</p> <ol> <li>Your code is sent to a proxy API route</li> <li>That route forwards it to Piston – an open source code execution engine running GCC 10.2</li> <li>The output comes back in under a second and displays in the browser</li> </ol> <p>That's it. No Docker on your machine. No backend you have to manage.</p> <h2> What it supports </h2> <ul> <li>C and C++ (GCC 10.2)</li> <li>Standard input (scanf, cin)</li> <li>Command line arguments (argc, argv)</li> <li>Separate stdout, stderr and compile error display</li> <li>Shareable links – your code is encoded in the URL</li> <li>Auto-saves to localStorage so you don't lose work on refresh</li> </ul> <h2> Tech stack </h2> <ul> <li>Next.js</li> <li>CodeMirror 6 (editor)</li> <li>Piston API (code execution)</li> <li>Vercel (hosting)</li> </ul> <h2> What's next </h2> <ul> <li>Error line highlighting (click a compile error, jump to that line)</li> <li>More language support</li> <li>Dark/light theme toggle</li> </ul> <p>Would love feedback from the community – especially C learners who <br> use online compilers regularly.</p> opensource programming showdev tools