Teach & Learn Code
With Live Playgrounds

Embed real code playgrounds in your courses. Students write, execute, and test code in 30+ languages — with instant feedback and auto-grading.

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Python.py

def fibonacci(n):

if n <= 1:

return n

return fibonacci(n-1)

JavaScript

const sum = arr

.filter(n => n > 0)

.reduce((a, b) => a + b)

Test Results3/3

Test 1: Basic input

Test 2: Edge case

Test 3: Large input

Java.java

public int factorial(int n) {

if (n <= 1) return 1;

return n * factorial(n-1);

}

Rust

fn main() {

let x = 42;

println!("{}", x);

}

Output

$ Running tests...

fibonacci(10) = 55

All tests passed

C++.cpp

#include <iostream>

int main() {

cout << "Hello";

}

Auto-Graded

Score100%

All test cases passed

TypeScript

interface User {

name: string

score: number

}

Debug

Line 5: IndexError

Hint: Check array bounds

Fixed! Tests passing

learn.example.com/code-playground

Editor

Python 3.11

def two_sum(nums, target):

# Find two numbers that add up to target

seen = {}

for i, num in enumerate(nums):

complement = target - num

if complement in seen:

return [seen[complement], i]

seen[num] = i

return []

# Test your solution

print(two_sum([2,7,11,15], 9))

Output

Run

$ python solution.py

[0, 1]

Executed in 24ms

Test Cases

Test 1: Basic pair

Input: [2,7,11,15], 9

[0, 1]

Test 2: Middle pair

Input: [3,2,4], 6

[1, 2]

Test 3: Same values

Input: [3,3], 6

[0, 1]

All tests passed!

3 of 3 test cases passed

3/3

Student's code

def solve(n):

return n * (n + 1) // 2

Executing

Execution complete

Output

Sandboxed

< 1 sec

Real Execution

Real code. Real output. Real learning.

No simulations or mock results. Student code runs in secure, sandboxed environments. Python, JavaScript, Java, C++, and 30+ languages — all executing real code with real output.

30+ Languages

Every language your course needs

From Python and JavaScript to Java, C++, Go, Rust, and beyond. 30+ programming languages are supported out of the box — students code in whatever language the course requires.

.py

Python

Data & scripting

.js

JavaScript

Web & frontend

.java

Java

Enterprise & OOP

.cpp

C++

Systems & algorithms

.rs

Rust

Systems & performance

.go

Backend & cloud

Auto-Grading

Define tests. Get instant results.

Set up expected inputs and outputs for each challenge. When students submit their code, it runs against your test cases automatically — they see exactly which tests passed and which failed.

Test: Basic input

solve(5)15

Test: Zero input

solve(0)0

Test: Large input

solve(100)5050

Test: Edge case

solve(-1)-1(expected 0)

Course Content

Variables & TypesLesson

Array ChallengeCode

Control FlowLesson

Function ChallengeCode

Embedded in your course

Course-Integrated

Code challenges inside your lessons

Embed code playgrounds directly into your course content. After a lesson on arrays, students immediately practice with a coding challenge — no context switching, no external tools.

Instant Feedback

Write, run, learn, repeat

The feedback loop is immediate. Students write code, hit run, see results in milliseconds, and iterate. Fast feedback means faster learning — no waiting for manual reviews.

Write

Write your solution in the code editor

Run

Execute code in a sandboxed environment

Check

See test results and output instantly

Iterate

Fix issues and resubmit your code