C · No sign-in needed
A C playground for small, readable programs.
Write and run C11 in your browser, with program input and console output. Keep an experiment short enough that you can explain each step.
Code runs in your browser. Guided course help requires sign-in.
Inspect a calculation before expanding it
Use printf to make intermediate values visible. With program input, check that the values you provide match the types your program expects. Source files compile together, and local headers can use quoted includes.
A few details to check
When a result surprises you, inspect one small part of the program before rewriting everything.
- Match printf format specifiers to the values you print.
- Initialize a variable before using its value.
- An array index must stay within the array’s bounds.
What this runtime supports
C11 runs in your browser. Source files compile together; use quoted includes for your local headers.
From an experiment to guided coursework
The public playground runs code without an account. Sign in to work in a personal course or a teacher-led class, where the tutor can use your code and run output when you ask a question. In a teacher-led class, your teacher can read the conversation and review saved code. Personal study is not shared with a teacher.
Questions you might have
Do I need to sign in to run C?
No. The public coding playground is free to try without signing in. Drafts stay in this browser. Guided course help and saved account work require sign-in.
Can I run any project here?
No. The playground is designed for learning experiments within its browser runtime. Review the supported features above, and keep examples small enough to inspect.
Choose a language. Try a small idea.
Project files, program input and output in your browser.