Firefox Developer Edition 142.0b9 Full Version Free Download

Download Firefox Developer Edition 142.0b9 – Offline Installer – Get the latest features, fast performance, development tools you need to build for the open web.

Overview of Firefox Developer Edition

Firefox Developer Edition has been rebuilt from the ground up to be faster and more powerful than ever. This includes a new CSS with state-of-the-art innovations and is blazingly fast.

In Firefox Developer E’s edition, the new Firefox DevTools is powerful, flexible, and hackable. This includes a best-in-class JavaScript debugger, which can target multiple browsers and is built in React and Redux.

Firefox is the only browser with tools built specifically for building and designing with CSS Grid. These tools allow you to visualize the grid, display associated area names, preview transformations on the grid, and much more.

Firefox DevTools has a brand new shape path editor that takes the guesswork out of fine-tuning your shape-outside and clip-path shapes by allowing you to fine-tune your adjustments quickly with a visual editor.

The new fonts panel in Firefox DevTools gives developers quick access to their information about the fonts being used in an element. It also includes valuable information such as the font source, weight, etc.

Firefox Developer Edition Features

Inspect and refine code to build pixel-perfect layouts.
Track CSS, JavaScript, security, and network issues.
Powerful JavaScript debugger with support for your framework.
Monitor network requests that can slow or block your site.
Add, modify, and remove cache, cookies, databases, and session data.
Test sites on emulated devices in your browser.
Fine-tune animations, alignment, and padding.
Unblock bottlenecks, streamline processes and optimize assets.
Find memory leaks and make your application zippy.
The only developer tool for inspecting the Web Audio API.
Edit, write, run, and execute JavaScript in real-time.
Edit and manage all your CSS stylesheets in your browser.

Technical Details and System Requirements

Supported OS: Windows 11, Windows 10, Windows 8.1, Windows 7
RAM (Memory): 2 GB RAM (4 GB recommended)
Free Hard Disk Space: 200 MB or more

Product Information

Created by

Firefox Setup 142.0b9.exe

Version

142.0b9

License type

freeware

Release Date

August 15, 2025

Languages

Multilingual

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