---
title: ".c file — what it is and how to open it"
description: "A .c file is a C Source. Source code in C, the language most operating systems are written in. How to open one on Windows, macOS and Linux, and what to convert it to."
url: https://atoneplace.net/file/c/
site: "At One Place"
---

# .c files

**.c file: C Source**

Source code in C, the language most operating systems are written in.

## What opens a .c file

- **Windows:** Visual Studio, Visual Studio Code, Notepad (built in)
- **macOS:** Xcode, Visual Studio Code, TextEdit (built in)
- **Linux:** Visual Studio Code, Text Editor (built in), Vim

## What a .c file is

C dates to 1972 and still underpins operating systems, embedded firmware and the runtimes of newer languages. A .c file is plain text compiled by gcc, clang or MSVC into a native executable. Its companion .h header files declare what the code offers to other files, which is why C projects always come in pairs.

## Converting it

A .c file is commonly converted to .exe, .o or .txt. It is a plain text format, so any text editor can open and edit it directly.

## Details

- **Extension:** .c
- **Full name:** C Source
- **Category:** Code and scripts
- **MIME type:** text/x-c
- **Created by:** Dennis Ritchie / Bell Labs
- **Format:** Plain text

## Common questions

### How do I open a .c file?

On Windows use Visual Studio; on macOS use Xcode; on Linux use Visual Studio Code. Source code in C, the language most operating systems are written in.

### What is a .c file?

C Source. C dates to 1972 and still underpins operating systems, embedded firmware and the runtimes of newer languages. A .c file is plain text compiled by gcc, clang or MSVC into a native executable.

### Can I convert a .c file?

Yes. It is usually converted to .exe, .o or .txt, either by exporting from one of the programs listed above or with a format converter.

## Related pages

- [.html — HyperText Markup Language](https://atoneplace.net/file/html/)
- [.js — JavaScript Source](https://atoneplace.net/file/js/)
- [.css — Cascading Style Sheet](https://atoneplace.net/file/css/)
- [.py — Python Source](https://atoneplace.net/file/py/)
- [.java — Java Source](https://atoneplace.net/file/java/)
- [.tsx — TypeScript Source (JSX)](https://atoneplace.net/file/tsx/)
- [.cpp — C++ Source](https://atoneplace.net/file/cpp/)
- [.php — PHP Source](https://atoneplace.net/file/php/)
- [.cs — C# Source](https://atoneplace.net/file/cs/)
- [.go — Go Source](https://atoneplace.net/file/go/)
- [.rs — Rust Source](https://atoneplace.net/file/rs/)
- [.rb — Ruby Source](https://atoneplace.net/file/rb/)

## Sources

- Media Types Registry — IANA (https://www.iana.org/assignments/media-types/)
- Official vendor product documentation — At One Place (/about/)