Run JS: Browser-based JavaScript Runtime

Press Release

Ataiva Releases Run JS: Instant JavaScript Execution in Your Browser

For immediate release - October 10, 2018

Sub-headline

Run JS provides developers with a seamless way to execute, test, and debug JavaScript code directly in Chrome, enabling rapid prototyping and website customization without leaving the browser.

The Problem

Web developers and JavaScript enthusiasts face a common challenge: quickly testing code snippets, prototyping ideas, or customizing websites requires cumbersome workflows. Traditional approaches involve switching between the browser and external editors, setting up local development environments, or using limited browser consoles that don’t persist code between sessions. This context-switching disrupts creative flow, slows down development, and creates barriers for quick experimentation or website customization.

The Solution

Run JS addresses these challenges by providing a powerful JavaScript runtime environment directly within Chrome. The extension allows developers to write, execute, and save JavaScript code that can interact with any website they visit. With features like syntax highlighting, persistent code storage per domain, and full DOM access, Run JS eliminates the need to switch between tools for quick code testing or website modifications. Whether you’re prototyping a new feature, debugging an issue, or customizing your favorite websites, Run JS streamlines the process by keeping everything within your browser.

Community Quote

“Run JS has completely transformed my workflow as a front-end developer,” says Maria Rodriguez, Senior Web Developer at TechSolutions Inc. “Before discovering this extension, I was constantly switching between my code editor and browser to test small JavaScript snippets or customize websites I use daily. Now, I can write and execute code directly in Chrome, and it automatically runs whenever I revisit those sites. During a recent client project, I used Run JS to quickly prototype different UI interactions and demonstrate them in real-time during our meeting. What would have taken hours of setup and back-and-forth now takes minutes. It’s become an essential tool in my development arsenal.”

How It Works

Run JS integrates seamlessly into your Chrome browser as an extension that’s always ready when you need it:

When you click the Run JS icon, a code editor window appears where you can write JavaScript code for the current website. The editor provides syntax highlighting and a clean interface for writing code comfortably. Once you’ve written your code, simply check the “enable” box and click “Save & Run” to execute it immediately.

What makes Run JS particularly powerful is its persistence feature—the extension saves your code for each domain you visit. Whenever you return to that website in the future, your custom JavaScript automatically executes, allowing for permanent customizations to your favorite sites. This enables countless possibilities, from adding new features to websites, removing annoying elements, automating repetitive tasks, or testing new ideas without modifying the actual website code.

The extension runs in a sandboxed environment for security while still providing full access to the page’s DOM, allowing you to manipulate website elements, add functionality, or extract data as needed.

Availability

Run JS is available now as a free extension in the Chrome Web Store. Users can install it directly from the Chrome Web Store page .

Get Started Today

Transform your web development workflow with Run JS. Visit the Chrome Web Store to install the extension and start executing JavaScript directly in your browser.

Frequently Asked Questions

Project Questions

What is Run JS?
Run JS is a Chrome extension that allows you to write, execute, and save custom JavaScript code for any website you visit. It provides a convenient code editor directly in your browser where you can create scripts that will run automatically whenever you visit specific websites. This makes it ideal for quick prototyping, website customization, debugging, and automating repetitive tasks without leaving your browser.

Why was Run JS created?
Run JS was created to streamline the web development workflow by eliminating the need to switch between browsers and code editors for quick JavaScript testing or website modifications. We wanted to provide developers with a tool that makes it easy to experiment with code, customize websites, and automate tasks directly within the browser environment where the code will ultimately run.

What can I use Run JS for?
Run JS can be used for a variety of purposes:

• Quickly testing JavaScript code snippets without setting up a development environment
• Customizing websites by adding features or removing unwanted elements
• Automating repetitive tasks on websites you frequently visit
• Prototyping new features or interactions for web applications
• Debugging website issues by injecting diagnostic code
• Creating userscripts that enhance website functionality
• Teaching or learning JavaScript with immediate feedback
• Extracting data from websites for personal use

How does Run JS compare to browser developer tools?
While browser developer tools provide a console for executing JavaScript, Run JS offers several advantages:

• Persistence: Your code is saved per domain and automatically runs on future visits
• Better editing experience: Dedicated code editor with syntax highlighting
• Organization: Separate scripts for different websites
• Automation: Automatic execution without manually opening developer tools
• Convenience: Quick access through the extension icon
• Sharing: Easier to save and share scripts compared to console snippets

Technical Questions

How does Run JS execute JavaScript code?
Run JS injects your custom JavaScript code into the webpage after it loads. The code runs in the context of the page, giving it access to the DOM and any global variables defined by the page. This allows your scripts to interact with and modify the website just as if the code was part of the original site. The extension uses Chrome’s content script API to inject and execute the code at the appropriate time in the page load cycle.

Is my code secure when using Run JS?
Your code runs in the same security context as the website you’re visiting. Run JS itself doesn’t transmit your code to any external servers—all scripts are stored locally in your browser’s extension storage. However, be cautious about the code you write, as it could potentially interact with sensitive information on websites. We recommend:

• Not running custom scripts on banking or financial websites
• Being careful with scripts that handle personal information
• Reviewing third-party scripts before using them
• Understanding that websites may have security measures that prevent certain script actions

Can Run JS access or modify content across different websites?
No, due to browser security restrictions, scripts you create for one domain cannot access or modify content on other domains. Each script is isolated to the specific website it was created for, following the same-origin policy enforced by browsers. This is a security feature that prevents potential cross-site scripting attacks.

Does Run JS work with all websites?
Run JS works with most websites, but some sites implement Content Security Policies (CSP) that may restrict the execution of injected scripts. Additionally, single-page applications or websites with complex JavaScript frameworks might require specific approaches to ensure your scripts run at the right time in the page lifecycle.

Implementation Questions

How do I install Run JS?
Installation is simple:

1. Visit the Run JS page on the Chrome Web Store
2. Click the “Add to Chrome” button
3. Confirm the installation when prompted
4. The Run JS icon will appear in your browser toolbar, ready to use

How do I create and run a script with Run JS?
Using Run JS is straightforward:

1. Navigate to the website where you want to run custom JavaScript
2. Click the Run JS icon in your Chrome toolbar
3. Write your JavaScript code in the editor window that appears
4. Check the “enable” checkbox in the top-right corner
5. Click “Save & Run” to execute and save your code
6. Your code will now run automatically whenever you visit this website

Can I disable a script temporarily without deleting it?
Yes, you can easily disable a script without losing your code:

1. Visit the website where your script runs
2. Click the Run JS icon to open the editor
3. Uncheck the “enable” checkbox in the top-right corner
4. Click “Save & Run” to update your preferences
5. The script will remain saved but won’t execute until you enable it again

How do I share scripts with other Run JS users?
While Run JS doesn’t have a built-in sharing mechanism, you can share your scripts by:

1. Opening the Run JS editor for the website
2. Copying the code from the editor
3. Sharing the code via email, messaging, or code sharing platforms
4. The recipient can then paste the code into their Run JS editor for the same website

Community & Support Questions

Where can I get help with Run JS?
Support resources include:

• The GitHub repository for bug reports and feature requests
• Community forums and discussions on web development platforms
• Stack Overflow using the “run-js-chrome” tag
• Direct feedback through the Chrome Web Store listing

Can I contribute to the development of Run JS?
Yes, contributions are welcome! As an open source project, you can contribute by:

• Submitting pull requests on GitHub
• Reporting bugs or suggesting features
• Improving documentation
• Creating tutorials or examples
• Helping other users in community forums

Is Run JS regularly updated?
Yes, Run JS receives updates to improve functionality, fix bugs, and add new features. The development team monitors Chrome API changes to ensure compatibility with new browser versions.

Are there any plans for versions on other browsers?
While Run JS was initially developed for Chrome, there are plans to expand to other browsers that support the WebExtensions API, such as Firefox and Edge. Check the project repository for the latest information on browser compatibility.

Key Features

Using Run JS

Common Use Cases