Night Reader Firefox

Night Reader

Reading comfortably with inverted brightness but preserved hue

Features & Capabilities

This extension eases your eyes by inverting the brightness of every webpage you browse. The majority of websites mainly use very light colors, but some already have a refreshing dark theme. For these the user can disable the domain, essentially setting it on a blacklist of the application. Its goal is, in contrast to the approach of creating new webpage–specific templates, to be as general as possible. This is best achieved by applying the CSS filter invert to the document root, because it inverts the whole area in one swoop after it got rendered normally instead of going through every element. This is even more efficient because CSS filters rely on the browser implementation, meaning all the good stuff like hardware acceleration or other system specific optimizations. Images should still show normally, but single elements cannot be excluded from the filter. This is no problem, since they can just get inverted on their own before the whole document gets inverted, reverting the images to their original color. To preserve the visual appearance of websites which may be iconic like the blue theme of Facebook, another filter is applied that rotates the hue back by 180 degrees. However, due to certain limitations of the RGB color model, very saturated colors get clipped in their value component that would have to exceed the maximum, resulting in occasional weird–looking images after they got reverted. Where an exact representation is needed, the hue–rotation can be disabled.

[TODO]

more ideas to be implemented in future releases are: — serve options page to input custom CSS rules to optimize other websites — friendly ui for options page (e.g. click [+] to add a rule, specify the case e.g. as regex, input CSS to be applied into text field) — keyboard shortcuts for enabling/disabling on domain and more — (maybe) make only–invert option domain specific — (maybe) optionally stop inverting input text fields — (do YOU have an idea? contact me!)

[KNOWN BUGS]

— (confirmed for Chrome) Prints get heavily pixelated when NightReader is enabled (even with "enabled globally" unchecked). There might be a possible fix in a future Version. Workaround: disable Extension for printing

[CHANGELOG]

[Version 1.7.41] fix for changed Twitter CSS improvements and tweaks for YouTube, Twitch, Twitch Beta, Wikipedia, TED and Bandcamp

[Version 1.7.4] made popup visually respond like websites (bg + css filter) adjustment for new YT theme (and other domains) updated preset blacklist

[Version 1.7.3] Updated predefined custom rules for twitch.tv (not inverting the dark theme) added predefined custom rules for bandcamp.com

[Version 1.7.2] Fixed/improved some of the predefined custom rules added message encouraging feedback

[Version 1.7.1] Bugfix: extension won't install because options page (WIP) was referenced but not found because it got excluded when packing extension

[Version 1.7] First public release of Night Reader Working:

  • inverting webpages via css filter at earliest possible stage (when loading a webpage)
  • inverting images etc. back to display normally
  • hue-rotating by 180 deg to achieve a brightness invert effect/preserving hues to keep the visual appearence as close to the original as possible
  • global quick extension disable switch
  • domain based blacklist managed by user
  • hidden CSS rules to further enhace and smoothen some features of a couple of popular websites like Facebook and Twitter
  • hue-rotation disable switch as workaround for loss of color information with very saturated colors

User Growth & Download Statistics

Manifest V2 Add-on
By:
Peter Nerlich
Daily users:
51
Rating:
4.11
(28)
Version:
1.7.42resigned1 Last updated: 2024-04-25
Version code:
5728556
Creation date:
2017-08-29
Risk:
Moderate risk impact Moderate risk likelihood
Permissions:
Content scripts matches:
  • *
Size:
107.36KB
Email:
pe*****@googlemail.com
URLs:
Website
Full description:
See detailed description
Source:
Firefox Add-ons Store
Data ingested on:
2026-06-15
Compare stats and ranking:

Other platforms

Chrome
Night Reader (v1.7.41)
1,000 4.67 (42)

Contact the developer

Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.
Developed by:
Peter Nerlich
Firefox Add-ons Store
https://addons.mozilla.org/firefox/addon/nightreader/
Email:
pe*****@googlemail.com
Website:
http://peter.nerlich4u.de/nightreader

User Reviews

you're helping vision for people that get line burns from reading text are dark background websites, tysm for saving my eyesight!!
by Fi*****, 2026-05-21

by 远离*****, 2025-04-16

by 敬念*****, 2025-03-11
View all user reviews ›

Is Night Reader Safe?

Risk impact
Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

Night Reader requires a few sensitive permissions. Exercise caution before installing.

Risk impact analysis details
  • Critical Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site.
  • High ******* ******* **** *** ****** ***** *** ***** ** ******* **** ********* ********* ** * *********** *****
Risk likelihood
Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Add-ons Store, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.

Night Reader is probably trust-worthy. Prefer other publishers if available. Exercise caution when installing this add-on.

Risk likelihood analysis details
  • High This extension website URL may be invalid
  • High **** ********* *** *** **** ****** ********* ********** *** *** ** ****** ** *****
  • Low **** ********* *** ******* **** **** * ****** **** ***** ******** *** **** ****** ** ** ****** *** *****
  • Low **** ********* *** ***** **** **** * ****** **** ***** ********** *** **** ****** ** ** ****** *** *****
  • Good **** ********* *** **** **** *******
Extension Guard
Extension Guard

Discover every extension in use, analyze risks, and enforce blocking policies with Extension Guard

Secure Your Browser
Upgrade to see full risk analysis details

Best Night Reader Alternatives

Here are some Firefox add-ons that are similar to Night Reader: