Drag & DropZones Firefox and Opera add-on extends the Firefox Search Engine manager window; you drag a Search Engine onto 1 (or more) DropZones to link them.

Web Assist for Chrome and Edge allows you to easily navigate the web, interact with web pages, dictate messages, and perform a wide range of tasks using your voice.

SEO Minion is an extension designed to assist with daily SEO tasks like On-Page SEO analysis, Broken Link Checking, Hreflang Checker, SERP Preview, Google Location Simulator, and more.

DuckDuckGo Privacy Essentials is the search engine that gives you excellent results and doesn't track you.
DuckDuckGo is also available for Windows 10/11/Mac, and Android.

Keyword Density Checker for Chrome, Edge, and Brave enables you to verify the frequency of a particular keyword in your content, helping you ensure that you are not overusing or underusing any specific keyword in your text.

Search by Image for Chrome, Firefox, Edge, and Opera is a powerful reverse image search extension/add-on that allows you to initiate a reverse image search from the right-click context menu or the browser toolbar with support for numerous search engines including Baidu, Bing, Google, Yandex, and TinEye.

uBlacklist for Chrome and Firefox removes specific sites from showing up in Google search.

Web Archives for Chrome, Firefox, Edge, Opera, and Safari allows access to cached versions of websites on multiple popular search engines, including the Wayback Machine, Google, and Bing.

MeasureSEO: Keyword Density Checker for Chrome allows you to check word keyword density and frequency.

Image Search Assistant for Chrome allows for the search of info about any image via multiple search engines.

Wayback Machine for Chrome, Firefox, Safari, and Android is an extension that allows you to access numerous archived web pages quickly.

Ask any question while you browse and receive the perfect answer in return with Perplexity for Chrome.

Ecosia sets your search engine to Ecosia and customizes your new tab page so you can plant trees with every search.

Dictionaries: one to rule them all for Chrome and Firefox integrates word lookups from various dictionaries.

Link Grabber for Chrome is an easy-to-use extension that allows hyperlink extraction and grabbing on an HTML page.

Save to Pocket for Chrome and Android is a browser extension that allows you to view things you find in Chrome later by simply putting them in Pocket.

Unpinterested! will remove Pinterest from your Google search results.

Simple Search for Chrome and Firefox overlays Google search results the way Google used to.

Survol for Chrome and Firefox enables a unique timesaving option for searching links, websites, articles, and more.

Bing-Google is a simple Firefox add-on that redirects any searches conducted with Cortana in Windows 10 from Bing to Google.