Firefox "about:config" Flags That I Like 🔥🦊

UPDATED [11/17/2024]: added new flags

 

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Here are some Firefox about:config flags that I have enabled. Most of these are for hardware video acceleration on Linux and personal "web viewing" preferences. Hope that some of you find them useful as well.

Hardware Video Acceleration for Linux

Option	Value
gfx.webrender.all	true
gl.require-hardware	true
layers.acceleration.force-enabled	true
media.av1.enabled	false
media.ffmpeg.vaapi.enabled	true
media.hardware-video-decoding.enabled	true
media.hardware-video-decoding.force-enabled	true
media.rdd-ffmpeg.enabled	true
media.rdd-ffvpx.enabled	true
media.rdd-vpx.enabled	false
media.utility-ffmpeg.enabled	true
widget.wayland-dmabuf-vaapi.enabled	true

The following is specifically for Nvidia Machines using libva-nvidia-driver (from elFarto/nvidia-vaapi-driver)

Option	Value	Reason
gfx.x11-egl.force-enabled	true	Required, this driver requires that Firefox use the EGL backend. It may be enabled by default. It is recommended to test it with the MOZ_X11_EGL=1 environment variable before enabling it in the Firefox configuration.
widget.dmabuf.force-enabled	true	Required on NVIDIA 470 series drivers, and currently REQUIRED on 500+ drivers due to a Firefox change. Note that Firefox isn't coded to allow DMA-BUF support without GBM support, so it may not function completely correctly when it's forced on.

 

Compact Mode Interface

Option	Value
browser.compactmode.show	true

 

Faster Content Painting

I prefer web pages to "paint" as early as it can, even if I am going to see some page breakage initially. I don't recommend this if you like good UX.

Option	Value	Comment
content.notify.backoffcount	5	This can be kept at the default value (-1), but I've just always had it at 5
nglayout.initialpaint.delay_in_oopif	0
nglayout.initialpaint.delay	0

Firefox 130+ Disable Tab Hover Behaviour

Option	Value
browser.tabs.hoverPreview.enabled	false
browser.tabs.hoverPreview.showThumbnails	false

Force System Emoji Font on Linux 🙂🐧

Option	Value	Comment
font.name-list.emoji	emoji	default value is Twemoji Mozilla (if things break for some reason)
gfx.font_rendering.fontconfig.max_generic_substitutions	127
gfx.font_rendering.opentype_svg.enabled	false

These flags disable the usage of the built-in Twemoji Mozilla Emoji font.

(workaround retrieved from Archwiki - Firefox#Font troubleshooting)