Dark mode for sites that don’t offer it
Last updated: 20 August 2026 · By the Eclipse team.
The short answer: before reaching for a tool, check three things — whether the site has a theme setting you have not found, whether it quietly follows your operating system preference, and whether its dark mode only appears once you are signed in. A surprising number of “no dark mode” sites have one of those. For the genuine long tail — documentation, forums, government portals, internal dashboards, older sites — a generated theme is the only option, and it is the case those tools exist for.
Step 1: find the setting you may have missed
Dark mode toggles hide in remarkably consistent places:
- Settings → Appearance, Theme, or Display
- The account or avatar menu in the top-right corner
- A sun/moon icon in the header or footer
- Inside a keyboard-shortcut command palette, on developer-oriented sites
Worth checking while signed in specifically. Many sites store the preference on the account, so a signed-out visitor sees only the light theme and reasonably concludes there is not one.
Step 2: check whether it follows your system
A large and growing number of sites implement the prefers-color-scheme media query and switch automatically with your OS, without ever showing a toggle. If you have never set your operating system to dark, you may be looking at light versions of sites that would happily go dark on their own.
Set your OS to dark — Windows: Settings → Personalisation → Colours; macOS: System Settings → Appearance — then revisit. This costs nothing and produces the best-looking result possible, because it is the site’s own hand-designed theme.
The three tiers of site support
| Tier | What you get | What to do |
|---|---|---|
| Full first-party dark theme | Designed dark palette, correct images and illustrations | Use it. Nothing beats it. |
| Partial support | Main app dark, but marketing pages, help centre, embedded widgets or emails stay light | Use theirs, and let a tool handle the gaps |
| None | Light only, no plans | Generated theme or Chrome’s flag |
The middle tier is the underrated one. Plenty of large services have a dark main application and an entirely light help centre, blog, status page or legal section. You click a support link and get flashbanged. A per-site tool that handles the gaps while deferring to the site’s own theme where it exists is exactly the right shape for this.
Where the long tail lives
The sites that will never ship dark mode are predictable, and they are the ones people actually spend hours in:
- Documentation and reference sites — many are excellent and many are old.
- Forums and community boards running long-lived software.
- Government and institutional portals, where redesign cycles are measured in years.
- Academic databases, journals and library catalogues.
- Internal tools and admin dashboards nobody has budget to restyle.
- Personal sites and older blogs.
A generated theme is genuinely the only answer here, and this is where the quality of the tool shows most — long-form reading is exactly where contrast tuning stops being cosmetic.
What still will not go dark
Set expectations before you start troubleshooting something with no fix. Charts and maps drawn into a <canvas>, embedded frames from other domains, images with baked-in white backgrounds, and the browser’s own PDF viewer are unreachable for architectural reasons — the full list of nine causes.
A sensible setup
- Set your OS and browser to dark. Free, and unlocks every site that already supports it.
- Turn on each site’s own dark mode where one exists.
- Add an extension that defers to those and fills in everything else.
- Use per-site overrides for the handful of pages the generated theme handles badly.
- Schedule it if you prefer light mode in daylight — the honest answer is that light mode is easier to read in a bright room.
Eclipse is built for exactly that arrangement: it respects a site’s own dark theme, applies a generated one everywhere else, keeps per-site preferences with no cap on how many sites you configure, and supports scheduling.
Try it yourself: Eclipse applies a generated dark theme to any site, with per-site overrides and live brightness and contrast controls. Free, no account, no site limits.
Product and website names mentioned here belong to their respective owners and are used only to describe what they do. Eclipse is an independent extension and is not affiliated with, endorsed by, or sponsored by any of them.
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