What are programming APIs?

Programming APIs provide services for code execution in multiple languages, syntax highlighting, static analysis, compiler access, documentation generation, and programming language data for building developer tools.

Is there a free code execution API?

Yes. Judge0 and Piston are free open source code execution APIs that support dozens of programming languages. They sandbox code execution in isolated containers for security.

Can I run code in the browser using an API?

Yes. By integrating a code execution API like Judge0 or Piston with your frontend, you can accept code input from users, send it to the API, and display the output in real time in the browser without any server-side code runner.

Programming Languages & Tools APIs

API	Description	Auth	HTTPS	CORS
Codeforces	Access Codeforces data including contests, user stats, and problem sets via API	apiKey	✓	?
Hackerearth	Compile and execute code in multiple programming languages using HackerEarth API	apiKey	✓	?
Judge0 CE	Open-source online code execution API supporting multiple languages	apiKey	✓	?
KONTESTS	Get data on upcoming and ongoing competitive programming contests	No	✓	?
Mintlify	Generate clean, interactive documentation for your code programmatically	apiKey	✓	✓

API

Description

Auth

HTTPS

CORS

Link

Codeforces

Access Codeforces data including contests, user stats, and problem sets via API

apiKey

✓

Hackerearth

Compile and execute code in multiple programming languages using HackerEarth API

apiKey

✓

Judge0 CE

Open-source online code execution API supporting multiple languages

apiKey

✓

KONTESTS

Get data on upcoming and ongoing competitive programming contests

✓

Mintlify

Generate clean, interactive documentation for your code programmatically

apiKey

✓

Best Programming APIs for Developers

A programming API allows developers to execute code in multiple languages, perform syntax highlighting, run static analysis, and access programming language metadata without setting up complex infrastructure. These APIs are the backbone of online IDEs, coding challenge platforms, and developer education tools.

CodeHelper's curated programming API collection includes APIs covering code execution, compilers, syntax highlighting, language references, and code quality analysis.

What to look for in a programming API

Language support: Verify the API supports all programming languages your platform targets, including version-specific runtimes.
Sandbox security: Code execution APIs must isolate user code in secure sandboxes to prevent malicious code from accessing host resources.
Execution timeout: Configurable timeouts prevent infinite loops from consuming resources and ensure consistent response times.

How to use this API directory

Browse the curated list of APIs below.
Click any API to visit its documentation.
Check the Auth column to understand what credentials you need.

Whether you are building an online IDE or a coding challenge platform, this free curated API directory saves you hours of research.

Programming APIs

Codeforces

Hackerearth

Judge0 CE

KONTESTS

Mintlify

Best Programming APIs for Developers

What to look for in a programming API

How to use this API directory

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