Built-in dark mode for web contents

[batata]

I love extensions like Dark Reader that automatically transform any website with a dark theme. The way they do this is by injecting many new styles into the DOM, it works but there is two main drawbacks to this method :
- there's a latency that makes contents blink
- it reduces performances on some websites by a lot

So It would be great if there could be a built-in low level solution (directly in web render?) that would swap colors on the fly without editing the page styles and thus would solve the two aforementioned issues.

[sus_scrofa]

I would also love to see the idea finally implemented. In the meantime, I'm using Ultima Dark, an open-source addon that is agressively enough and avoids white flickering: https://addons.mozilla.org/en-US/firefox/addon/ultimadark/

(I'm not affiliated in any way with the development of the addon, just a user of it.)

It would be a dream to have this feature implemented di into firefox, since the source code already exists, so I could not just decide if I want a website to use enhanced tracking protection, my webcam, microphone etc. but also if I want a website to be darkened or not (e.g. because it already has a great dark mode)

[SphinxMan]

Seems like this has been kicking around for a few years now. I really want to like Firefox, but having an (albeit open source) extension be able to read every site I log in to doesn't sit well with me. I tend to use Brave if I have to do anything banking or medical related and Firefox for more casual stuff.

The trouble is, once I have Brave open in the evening, then I just carry on using it and it works beautifully, so there's no impetus to return to Firefox. I mostly use Firefox at work now, because I work during the day and this missing feature doesn't bother me when the sun's up!

[Puskara]

Make Dark Mode the browser default or request both light and dark by default

Many folks seem to prefer dark-mode.  IME the prevalence of light-mode is purely because it is the default.  Many users would prefer to use dark-mode but won't as light-mode is the default and making this change exposes them to a higher risk of fingerprinting and thus a loss of privacy.

My proposal is to make dark-mode the default for all Mozilla browsers.  This will mean that everyone will get to enjoy the benefits of dark-mode while not compromising privacy.  Alternatively, Mozilla could change the browser to always request both light & dark data and hide what the user is actually seeing behind a layer of abstraction which would always give a standardized response to what mode is being used.  This would preserve everyone's privacy and would allow everyone to select light or dark mode as they saw fit.

[Jon]

(Note: similar ideas have been merged into this thread)

[adelin]

Is the Firefox development team experimenting with this feature in the source code, or preparing it for release?

I accidentally managed to enable it once, but I have not been able to reproduce it since. 😞

I was testing the new feature that allows remapping hotkey combinations, and I had just replaced CTRL+SHIFT+P with CTRL+SHIFT+N.

For a brief moment, while the shortcut worked normally in other windows outside the one where I had the `about:preferences` tab open, pressing CTRL+SHIFT+N in the main window in other tabs caused the page to toggle between the normal appearance and a rendered dark mode.

Unfortunately, I could no longer reproduce it afterward. It only worked until I switched focus away from the window. Still, I have to say, I was impressed by how good the dark rendering looked.

I am not using any dark mode extension whatsoever, so this appeared to be a native feature.

If anyone has any information about it, please share.

Thanks.

[prem-mahi]

Temporarily, one can use about:preferences#accessibility > Website Contrast function to invert both background & foreground custom colors to a comfortable dark mode palette you want. This'll bork the entire webpage's built-in styling shades & give you a completely bland outline based look. But in some ways, it does look good and you'll get on with it. Try it guys !

[daveking1000]

I've done that, and it looks bad. I am currently using an extension, Dark Reader, which is decent. Sometimes black on white icons are made black on black, unfortunately. The developer does provide a way to set up site-specific fixes for this, but I'm no programmer. But thinks like this should be done natively. Some sites haven't gotten to it.

[daveking1000]

I have done it that way, and it looks bad. I am currently using an extension, Dark Reader, that does a decent job. Some black on white icons get rendered black on black, though. The developer has provided a way to upload site-specific fixes for that, but I'm no programmer

[prem-mahi]

Contrast dark mode does look off because it completely overshadows webpage styling. But, it also introduces outline boxes too. It kinda looks retro, which I personally came to like it more.

It's also way faster than any dark mode extensions out there. Even faster than native light mode, because the contrast mode removes all kinds of rich webpage rendering backgrounds and replaces with it's own outlines.

I like gruvbox brownish retro look. You can check my contrast theme here. Most websites do look amazing if chosen the right color palettes.

[prem-mahi]

I like gruvbox brownish retro look. You can check my contrast theme here. Most websites do look amazing if chosen the right color palettes.

[aliyarkhan]

Summary

Add a built-in preference that forces all web content to render in dark mode, similar to Chromium's Auto Dark Mode for Web Contents (chrome://flags/#enable-force-dark).

Problem

Firefox currently supports the prefers-color-scheme media query, which works only for websites that have implemented a dark theme.

A large number of websites still provide only a light theme. Users who prefer dark mode must install third-party extensions such as Dark Reader, which:

• Consume additional memory and CPU.
• Inject scripts into every page.
• Require permission to read and modify website content.
• May introduce compatibility issues.
• Are not suitable for privacy-conscious users who prefer native browser functionality.

Firefox already provides an excellent native dark browser interface, but there is no built-in way to force web pages into a dark appearance.

Proposed Solution

Introduce a browser preference (and optionally an experimental flag) such as:

browser.force_dark_mode

or

layout.force-dark.enabled

with a corresponding Settings option:

Settings → General → Appearance

☑ Force Dark Mode for Web Pages

The browser would automatically transform pages that do not provide a dark theme.

Possible rendering strategies include:

• Color inversion with intelligent image detection.
• CSS color remapping.
• Algorithmic darkening similar to Chromium's Auto Dark Mode.
• GPU-assisted color transformations where appropriate.

Benefits

• Native implementation without requiring extensions.
• Lower memory and CPU usage than JavaScript-based extensions.
• Better privacy since no extension needs permission to inspect page content.
• Consistent user experience across all websites.
• Improved accessibility for users who are sensitive to bright interfaces.
• Reduced battery usage on OLED displays when dark colors are used.

Compatibility

The feature should:

• Respect websites that already provide a dark theme.
• Allow per-site exceptions.
• Be disabled by default if compatibility concerns exist.
• Be available initially behind an about:config preference or experimental feature.

Why This Matters

Dark mode has become a standard feature across operating systems and browsers. Chromium-based browsers already provide an experimental implementation that many users rely on. Firefox users currently need third-party extensions to achieve the same functionality.

Providing a native implementation would improve accessibility, privacy, and the overall user experience while reducing dependence on extensions.

Thank you for considering this enhancement.

[Jon]

(Note: similar ideas have been merged into this thread)