Web Sandbox – Test HTML, CSS, JavaScript & PHP Online

Test and experiment with HTML, CSS, JavaScript, and PHP directly in your browser. Write code, see the result in a live preview, check console output, and share your sandbox when you need someone else to review it.

Live Preview
PHP Code
Console Output
Share Sandbox

Generate a public link to share this sandbox with others.

Note: Code shared publicly will be saved to our servers.

Pro Feature: Save private sandboxes to the cloud to access them anywhere. Sign in to Upgrade

What Is a Web Sandbox?

A web sandbox is an online environment where you can write and test code without setting up a local development project.

It is useful for trying out a small piece of HTML, CSS, JavaScript, or PHP when you want to see how something works without creating a full application.

DevToolbox provides two modes: an HTML/CSS/JS sandbox for frontend code and a PHP mode for running small PHP snippets.

HTML, CSS and JavaScript Sandbox

Use the frontend sandbox to write HTML, CSS, and JavaScript and see the result in the live preview.

It can be useful for testing:

  • HTML layouts

  • CSS styles

  • Flexbox and Grid layouts

  • JavaScript functions

  • UI components

  • Small frontend experiments

  • Responsive design ideas

  • Browser-based code examples

The preview updates inside the browser, making it easy to make a change and immediately see the result.

Test PHP Online

The PHP mode lets you run small PHP snippets without setting up a local PHP server.

You can use it to test things such as:

  • PHP arrays

  • String functions

  • Loops and conditions

  • Small algorithms

  • Basic PHP syntax

  • Function behavior

  • Simple code experiments

PHP code is sent to the server for execution, with the output returned to the sandbox console.

How to Use the Web Sandbox

Using the sandbox is simple:

  1. Choose HTML/JS/CSS or PHP Backend mode.

  2. Write or paste your code into the editor.

  3. Run or preview the code.

  4. Check the live output or console.

  5. Make changes and test again.

For frontend experiments, the live preview lets you see your changes without repeatedly refreshing a separate page.

Test Frontend Code Without a Local Setup

You don't always need a full development environment to test a small piece of code.

A browser-based sandbox can be useful when you want to quickly check whether a CSS rule works, experiment with a JavaScript function, or build a small UI example.

It's also convenient when you're working from a computer where you don't have your usual development tools installed.

Use jQuery in the Sandbox

The HTML/CSS/JS sandbox includes an option to include jQuery.

This can be useful when testing older frontend code, experimenting with jQuery selectors and events, or checking a small jQuery-based example without setting up a separate project.

Share a Sandbox

You can generate a public link to share a sandbox with other people.

This is useful when asking for help with a code problem, sharing a small frontend example, demonstrating a bug, or showing someone how a particular piece of code works.

For sensitive code or credentials, avoid putting confidential information into a shareable sandbox.

When Should You Use an Online Code Sandbox?

An online sandbox is useful for small experiments and quick tests where setting up a complete project would take more time than the actual task.

Common uses include:

  • Testing a JavaScript function

  • Experimenting with CSS

  • Creating a quick HTML example

  • Testing a UI component

  • Debugging a small frontend snippet

  • Running a PHP example

  • Preparing a reproducible code example

  • Sharing a small coding experiment

For larger applications, a local development environment or full IDE will usually provide more control and project management features.

Frequently Asked Questions

A web sandbox is an online environment for writing and testing code in a controlled workspace. It is commonly used for experimenting with HTML, CSS, JavaScript, and other web technologies.

Yes. You can write HTML, CSS, and JavaScript in the frontend mode and view the result in the live preview.

Yes. The PHP Backend mode allows you to run small PHP snippets and view their output in the console.

No. The sandbox runs through your web browser, so you can use it without installing a local development environment.

Yes. The frontend sandbox includes an option to include jQuery when you need it for an experiment or code example.

Yes. The Share Sandbox feature can generate a public link that you can send to other people.

Not exactly. A sandbox is designed for quick experiments, testing, and small code examples. A full IDE generally provides more features for managing larger projects and applications.

The privacy of your code depends on the mode and features you use. Frontend code runs in the browser, while PHP code is sent to the server for execution. Avoid entering passwords, API keys, or other confidential information into an online sandbox.