Explore 2021's Top Open‑Source Chrome Extensions: Dark Reader, Tab Manager Plus & Stylus

At the end of 2021 Google released its list of the most popular Chrome extensions, and among the 13 entries several open‑source tools stand out. This article highlights three of them—Dark Reader, Tab Manager Plus, and Stylus—explaining their purpose, how to install them, and providing sample code.

Dark Reader

Dark Reader is a long‑standing open‑source extension that adds a dark mode to any website, allowing one‑click toggling and fine‑grained control over brightness, contrast, and sepia.

It can be installed in three ways:

From NPM as a package

By building from source (NPM run API)

Via a CDN such as unpkg or jsDelivr

Example usage of the Dark Reader API:

DarkReader.enable({
    brightness: 100,
    contrast: 90,
    sepia: 10
});

DarkReader.disable();

// Enable when the system color scheme is dark.
DarkReader.auto({
    brightness: 100,
    contrast: 90,
    sepia: 10
});

// Stop watching for the system color scheme.
DarkReader.auto(false);

// Get the generated CSS as a string.
const CSS = await DarkReader.exportGeneratedCSS();

// Check if Dark Reader is enabled.
const isEnabled = DarkReader.isEnabled();

ES‑module style import example:

import {
    enable as enableDarkMode,
    disable as disableDarkMode,
    auto as followSystemColorScheme,
    exportGeneratedCSS as collectCSS,
    isEnabled as isDarkReaderEnabled
} from 'darkreader';

enableDarkMode({
    brightness: 100,
    contrast: 90,
    sepia: 10,
});

disableDarkMode();

followSystemColorScheme();

const CSS = await collectCSS();
const isEnabled = isDarkReaderEnabled();

The current version at the time of writing is v4.9.43.

Tab Manager Plus

Tab Manager Plus helps developers manage many open Chrome tabs by providing search, move, and save capabilities, along with visual thumbnails of all tabs and windows.

Key features include highlighting duplicate tabs, one‑click closing of all but selected tabs, and an overview thumbnail view that makes locating a specific tab fast and intuitive.

Creating a new window and dragging tabs into it is straightforward, as shown in the screenshots.

The latest version mentioned is 5.2.0.

Stylus

Stylus is a stylesheet manager for customizing the appearance of websites, continuing the development of the discontinued Stylish extension.

It allows users to apply custom CSS themes to any site, giving a personal look and feel to the browsing experience.

The current version is v1.5.22, and the interface provides easy access to installed styles.

These three extensions are free, open‑source, and widely used, making them valuable tools for developers who want to improve their browsing workflow.