Night Viewer is a lightweight and free browser extension that enables dark mode for the View Page Source. Not only that, it also shows you how the browser has rendered a page’s original HTML into a functioning DOM, including modifications made by JavaScript. Night Viewer allows you to modify the font size of the View Page Source by increasing or decreasing it to make it more readable.

Night Viewer core features

Beautify the source code to make it more readable

Modify the font size at the View Page Source

Before and after JS execution view

  • Initial code - shows you the source code before the JavaScript execution (returned from server)
  • Current code - shows you the source code after the JavaScript execution (same as Developer Tools)

We care about your Privacy

Instead of simply pointing you to our privacy policy. We would like to address this topic in the most understandable language here.
This extension is serverless - no requests are being made. The only data it collects and stores locally (on your computer) is what type of font have you chosen and the preferred source code view.

How much does it cost?

Night Viewer is completely FREE extension that is developed by the team behind one of the best dark mode extensions - Night Eye

If you enjoy using Night Viewer, you can support its development with a donation.

You might also like Night Eye - the dark mode extension

Night Eye is a browser extension that enables dark mode on nearly any website. It works on all major browsers and comes with 3 months of completely free trial. No credit card or personal details are required for you to test it out. More details here -