Firefox Nightly gets ability to translate selected text passages

Since Firefox 118, released in September 2013, the open source browser has been able to translate entire websites by clicking on an icon in the address bar. Unlike Google Translate and the like, the automatic translation into other languages takes place on your own computer, not on a third-party internet server. The current nightly release of Firefox extends this feature so that you can use Firefox Translate to translate snippets of text rather than entire web pages.

If you want to use this feature to translate selected passages of text, you will need to use the latest Firefox Nightly build, which is available on Debian and Ubuntu, for example, via a repository set up by Mozilla. You will also need to enable this feature by typing "about:config" in the address bar and double-clicking "browser.translation.select.enable" (the option must be set to "true").

Now when you select text on a web page with the mouse, Firefox will offer a new entry "Translate selection to <language>" in the context menu, and a small pop-up window will appear. This is different from translating entire web pages in Firefox, which directly replaces the web page text with the translated version. The new "Translate" pop-up offers options to select the source and target languages to translate into, a small "Copy" button, and the option to translate the entire web page.

Although the "Translate selected text" option has been available since Firefox 124, the feature is only available in Firefox Nightly 126 alpha. It is expected that the "Translate selected text" option will be available in Firefox 126, which will be released in May.