Guide to Firefox about:support Diagnostic Details

The about:support page in the Mozilla Firefox web browser, officially titled the Troubleshooting Information page, provides a comprehensive summary of the browser's internal configuration and environment. This article examines three critical diagnostic sections found on this page: graphics drivers and rendering specifications, important modified preferences, and active extensions. Understanding these specific summaries allows users to efficiently pinpoint the root causes of browser crashes, visual glitches, and unexpected behavioral changes.

Graphics Drivers and Rendering Specifications

The Graphics section is one of the most detailed areas on the about:support page, offering a complete breakdown of how Firefox interacts with your computer's visual hardware. It is primarily used to diagnose video playback issues, screen flickering, high CPU usage, and hardware acceleration crashes.

Key diagnostic details in this section include:

  • Features and Compositing: Displays the current rendering engine in use, such as WebRender or Software WebRender. This immediately tells you if Firefox is successfully using your graphics card for hardware acceleration or falling back on your CPU.
  • GPU Specifications: Lists data for your primary (GPU #1) and secondary (GPU #2) graphics cards. It reveals the exact hardware description, Vendor ID, Device ID, allocated RAM, and whether the GPU is currently active.
  • Driver Information: Provides the exact driver version, the driver release date, and the specific driver files being utilized by the operating system. Outdated dates here are the primary indicator that a user needs to update their graphics card drivers.
  • WebGL Driver Info: Shows the renderer and version strings for WebGL 1 and WebGL 2, which are essential for running 3D graphics and complex web applications in the browser.
  • Decision Log: Tracks internal checks Firefox performs during startup. It explains why certain graphics features (like Direct2D, Vulkan, or hardware video decoding) are enabled, disabled by default, or blocked due to known driver bugs.
  • Failure Log: Records any real-time graphics errors or driver resets that have occurred during the current browsing session.

Important Modified Preferences

Firefox allows deep customization through its advanced configuration editor (about:config), but changing these settings can sometimes break website functionality or degrade performance. The about:support page does not list every single setting in the browser; instead, it filters and displays only the "Important Modified Preferences."

Key diagnostic details in this section include:

  • Altered about:config Entries: Displays an alphabetical table of core preferences that have been changed from their factory default values, alongside their current boolean (true/false), integer, or string values.
  • Whitelisted Categories: Focuses strictly on preferences known to impact stability, security, and rendering. These typically start with prefixes like accessibility., browser.cache., dom., extensions., gfx., media., network., privacy., and security..
  • user.js Preferences: Indicates right below the main table whether a user.js file exists in the profile folder. This file can forcefully overwrite preferences every time Firefox starts, often without the user's knowledge if placed there by third-party software.
  • Important Locked Preferences: Lists settings that have been permanently locked by a system administrator or enterprise policy, preventing the user from changing them.

Active Extensions and Add-ons

Extensions are a frequent source of memory leaks, slow page loads, and layout issues on websites. The Add-ons section on the about:support page provides a clean, exportable inventory of every extension, theme, and language pack installed in the current Firefox profile, without requiring you to navigate through the visual Add-ons Manager.

Key diagnostic details in this section include:

  • Name and Type: Clearly identifies the human-readable name of the add-on and categorizes it as an extension, theme, or locale (language pack).
  • Version: Shows the exact version number of the installed add-on. This helps verify if an extension is outdated and potentially incompatible with the current version of Firefox.
  • Enabled Status: Uses a simple true or false value to separate active extensions from those that are installed but currently disabled. Only extensions marked as true actively inject code or modify browser behavior.
  • ID: Displays the unique internal identifier string (often formatted like an email address or a UUID in curly brackets) assigned to the extension. This ID is necessary for locating the extension's specific files inside the local Firefox profile folder or looking up the extension in malware databases.