Flagfox

Enables you to better understand the evolution of browser fingerprints (which is what websites use to uniquely identify and track you). Download: Chrome - Firefox

Block fingerprint without removing access to HTML5 Canvas element. Canvas fingerprinting is commonly used for tracking, this extension helps to mitigate this through disallowing the browser to generate a true unique key Download: Chrome - Firefox - Edge

This extension will automatically remove tracking elements from the GET parameters of URLs to help protect some privacy Download: Chrome - Firefox / Source

Similar to LocalCDN, Serves up local versions of common scripts instead of calling to 3rd-party CDN. Improves privacy and load times. Works out-of-the-box and plays nicely with regular content blockers. Download: Chrome - Firefox - Opera - Pale Moon - Source

Firefox Multi-Account Containers lets you keep parts of your online life separated into color-coded tabs that preserve your privacy. Cookies are separated by container, allowing you to use the web with multiple identities or accounts simultaneously. Download: Firefox

A browser extension that redirects popular sites to alternative privacy friendly frontends Download: Firefox - Chrome

Linguist is a privacy‑focused translation solution in-browser that has an embedded offline translator and lets users create custom translators to use any translation API, even if it's locally deployed. Full-page translation, selected text translation, dictionary, history, and other features you may expect of a full-featured translation solution in-browser. Download: Chrome / Firefox

Emulates remote frameworks (e.g. jQuery, Bootstrap, Angular) and delivers them as local resource. Prevents unnecessary 3rd party requests to tracking CDNs Download: Firefox

Notifies you when visiting a known or potential phishing site, and detects suspicious JavaScript (including skimmers and miners). Also provides a simple rating for a given site's legitimacy and security. Great for less technical users. Netcraft also has a handy online tool: Site Report for checking what any given website is running. Download: Chrome \ Firefox \ Opera \ Edge

Blocks invisible trackers, in order to stop advertisers and other third-parties from secretly tracking where you go and what pages you look at. Less configurable but simpler than uBlock, and focuses on trackers only without blocking ads. Download: Chrome - Firefox

Simple extension by DuckDuckGo, which grades the security of each site. Download: Chrome
Firefox

Prevent Firefox from sending Origin headers when they are least likely to be necessary, to protect your privacy Download: Firefox - Source

The companion extension for PrivacySpy.org - an open project that rates, annotates, and archives privacy policies. The extension shows a score for the privacy policy of the current website. Download: Chrome - Firefox

Some web pages use intermediary pages before redirecting to a final page. This add-on tries to extract the final url from the intermediary url and goes there straight away if successful Download: Firefox - Source

Block ads, trackers and malware sites. Download: Chrome - Firefox

Spoofs browser's User-Agent string, making it appear that you are on a different device, browser and version to what you are actually using. This alone does very little for privacy, but combined with other tools, can allow you to keep your fingerprint changing, and feed fake info to sites tracking you. Some websites show different content, depending on your user agent. Download: Chrome - Firefox - Edge - Opera - Source

View archived and cached versions of web pages on 10+ search engines, such as the Wayback Machine, Archive.is, Google etc Useful for checking legitimacy of websites, and viewing change logs Download: Firefox - Chrome - Edge - Source

Provides user control over WebRTC privacy settings in Chromium, in order to prevent WebRTC leaks. Download: Chrome. For Firefox users, you can do this through browser settings. Test for WebRTC leaks, with browserleaks.com/webrtc