Some websites still don’t have a dark mode. Your eyes suffer at midnight. Here’s a two-second fix that works on any page — desktop or mobile.

The Trick

The trick uses a single CSS rule injected into the page:

html {
  filter: invert(100%) hue-rotate(180deg) !important;
}
img, video, picture, canvas {
  filter: invert(100%) hue-rotate(180deg) !important;
}

invert(100%) flips every colour to its opposite — white becomes black, black becomes white. That alone would also invert photos and videos, turning them into negatives. The second hue-rotate(180deg) cancels out the colour shift on images and videos by rotating hues back around the colour wheel, so photos look natural while the UI is dark.

The result: a convincing dark mode on literally any website, with no extension needed.

On Desktop — Using the DevTools Console

Every major desktop browser has a built-in JavaScript console. Open it, paste one line, and the page goes dark.

Open the Console

You can also reach it via F12 → click the Console tab.

Inject Dark Mode

Click in the console, paste the following, and press Enter:

(function () {
  let style = document.createElement('style');
  style.id = '__brute-dark';
  style.innerHTML = 'html { filter: invert(100%) hue-rotate(180deg) !important; } img, video, picture, canvas { filter: invert(100%) hue-rotate(180deg) !important; }';
  document.head.appendChild(style);
})();

The page immediately switches to dark mode. No extensions, no settings — just paste and go.

Revert It

To put the page back to normal without refreshing, paste this into the console:

(function () {
  let el = document.getElementById('__brute-dark');
  if (el) el.remove();
})();

Or just refresh the page — the injected style only lives in memory and disappears on reload.

Try It Right Here

See it in action on this page before you copy the code anywhere:

On Mobile — Using a Bookmarklet

On a phone or tablet there’s no DevTools. But there is another trick: bookmarklets. A bookmarklet is a bookmark whose “URL” is a snippet of JavaScript. Tapping it runs the code on the current page.

Step 1 — Create the Dark Mode Bookmarklet

Bookmark any page, then edit that bookmark:

• Name: Dark Mode ON
• URL: delete everything and paste this exactly:

javascript:(function(){let s=document.createElement('style');s.id='__brute-dark';s.innerHTML='html{filter:invert(100%) hue-rotate(180deg) !important;}img,video,picture,canvas{filter:invert(100%) hue-rotate(180deg) !important;}';document.head.appendChild(s);})();

Save it.

Step 2 — Create the Revert Bookmarklet

Create a second bookmark:

• Name: Dark Mode OFF
• URL:

javascript:(function(){let e=document.getElementById('__brute-dark');if(e)e.remove();})();

Save it.

Step 3 — Use Them

Navigate to any page you want to darken. Tap your address bar, type Dark Mode ON, and select the bookmark from the suggestions when it appears.

To restore the original look, do the same with Dark Mode OFF.

Why This Works

Browsers let any JavaScript running on a page freely modify the page’s HTML and CSS. Injecting a <style> tag is the same thing web developers do all the time — we’re just doing it at runtime from the outside.

The !important flag overrides whatever CSS the site already applied, so the filter wins even on sites with complex stylesheets.

Because the style is tagged with a unique id, the revert script can find and remove it precisely without disturbing the rest of the page.

Caveats

• Doesn’t survive a refresh. Each page load starts fresh, so you’ll need to re-run the bookmarklet. If you want a permanent solution, a browser extension like Dark Reader is the right tool.
• Some pages look a little odd. Sites that use SVG icons or CSS gradients may look slightly off, but it usually works well enough for reading.
• Videos stay natural. The double-invert trick keeps photos and videos looking correct, so you won’t be watching a negative-colour film.

Want more browser hacks you can pull off without installing anything? Check out Edit Any Webpage in Seconds and Hacking Wordle with DevTools.