If you want to use a search engine that is not preinstalled in your browser, you can add it manually by following these steps:

Chrome: To add a custom search engine in Chrome, go to Settings > Search engine > Manage search engines and click Add. Enter the name, keyword, and URL of the search engine and replace the query term with %s. For example, to add Ecosia, enter "Ecosia" as the name, "eco" as the keyword, and "https://www.ecosia.org/%s" as the URL. Then click Add and make it your default search engine. ¹⁰

Firefox: To add a custom search engine in Firefox, go to Options > Search and click Find more search engines at the bottom of the page. You will be directed to the Firefox Add-ons website, where you can search for and install additional search engines. To add a new search engine, click the Add to Firefox button next to the search engine you want and confirm by clicking Add in the pop-up box. Then go back to the Options page and select the search engine from the drop-down menu under Default Search Engine. ¹²

Edge: To add a custom search engine in Edge, visit the website of the search engine you want to use and perform a search. Then, go to Settings > Privacy, search, and services > Address bar and search > Manage search engines and click Add. Enter the name and URL of the search engine and replace the query term with %s. For example, to add Ecosia, enter "Ecosia" as the name and "https://www.ecosia.org/%s" as the URL. Then click Add and make it your default search engine. ¹¹

Safari: To add a custom search engine in Safari, you will need to install a third-party extension, such as AnySearch. After installing the extension, go to Safari > Preferences > Extensions and enable AnySearch. Then go to Safari > Preferences > Search and select AnySearch as the default search engine. You can customize the search engine URL in the extension settings. ¹⁰