MyWebUtils: Free Online Dev Tools
JavaScript Runner
Write and execute JavaScript code snippets directly in your browser and see console output.
About the JavaScript Runner
What is a JavaScript Runner?
A JavaScript Runner, often called a "REPL" (Read-Eval-Print Loop) or a "scratchpad," is an interactive environment for writing and executing JavaScript code snippets on the fly. It's a quick and simple way to test logic, experiment with language features, or debug a function without the need to set up a full HTML page or a Node.js project.
Why is This a Must-Have for Developers?
- Instant Prototyping: Quickly test an algorithm, a data transformation, or a utility function before integrating it into a larger application.
- Learning & Experimentation: It's the perfect environment for learning new JavaScript features (like `async/await` or array methods) or for trying out code snippets from tutorials and documentation.
- Debugging: Isolate a problematic function from your main codebase and run it here with different inputs to pinpoint errors in a controlled environment.
- Console Interaction: Our tool captures all `console` outputs (`log`, `warn`, `error`, etc.), allowing you to see the results of your code just as you would in your browser's developer console.
How to Use It
Write your JavaScript code in the input area on the left. Click the "Run Code" button. All `console` outputs and any runtime errors or exceptions will be displayed in the output area on the right, giving you immediate feedback on your code's execution.