Next time you’re staying up till three in the morning mindlessly watching YouTube videos, why not give your eyes a rest and turn the lights out? As discovered by Reddit, YouTube now a secret dark mode that’s easy to activate. Here’s how you do it:

Make sure you have the most recent version of Google Chrome (that’s version 57 onwards)

Open up the developer window by hitting Ctrl + Shift + I on Windows, or Option + Command + I on Mac

Select the “console” tab

Paste in the following text: document.cookie="VISITOR_INFO1_LIVE=fPQ4jCL6EiE" and hit enter

Close the developer window, refresh your browser, and the dark mode toggle is available in the main settings menu in the top right. Turning it on is as easy as flicking a light switch:

This feature hasn’t yet been officially announced, but it’s part of a number of changes YouTube is testing for the website’s design. To our eyes it looks pretty slick, and hopefully will be here to stay. Happy browsing.