JS Code Generator

⚙️ Run JavaScript Code Online | Newtum Online JavaScript Runner

Write, test, and run JavaScript code online with Newtum's fast, browser-based JavaScript code runner. Whether you're learning the basics, testing logic, or working with APIs using fetch or XMLHttpRequest, Newtum makes it easy—no installation required.

Perfect for beginners, frontend developers, and QA professionals working with web APIs.

✅ Benefits of Using Newtum JavaScript Code Online

• 🚀 No setup needed – Code runs directly in your browser
• 🔍 Real-time output – See results and errors instantly
• 📡 Test APIs using fetch, axios, or XMLHttpRequest
• 🧰 Interactive console for debugging
• 🔐 Secure sandboxed environment
• 🧑‍💻 Great for learners, coders, and testers

🌐 Use JavaScript to Test APIs

JavaScript is a great language for API testing right in the browser. With built-in tools like fetch() and third-party libraries like axios, you can send GET/POST/PUT/DELETE requests, handle JSON/XML responses, add headers and authentication, and validate response status codes and data. Use JavaScript to simulate frontend calls or test your API endpoints without needing Postman or CLI tools.

📄 JavaScript Examples

fetch("https://jsonplaceholder.typicode.com/posts/1")
  .then(response => response.json())
  .then(data => console.log(data))
  .catch(error => console.error("Error:", error));

async function getData() {
  try {
    let response = await fetch("https://jsonplaceholder.typicode.com/users");
    let users = await response.json();
    console.log(users);
  } catch (err) {
    console.error("Fetch failed:", err);
  }
}

getData();