This userscript mimicks chrome's built-in page translator. It can be used as a userscript (from the context menu, or, always on) or as a bookmarklet (clicking the bookmark translates the page). Works in Firefox and in chrome. It has been tested with Tampermonkey and Violentmonkey.

Since June 2023, the built-in translation in old versions of chrome has stopped working. This sparked the idea to bring the feature back to those users who are still sticking to their old programs, and make it more flexible and browser independant. It should works in all versions of Firefox and chromium-based browsers. If you experience problem in older versions, feel free to contact me.
The only cave-at is that it uses google translate. You are warned.

Webmasters have always been able to add a widget to integrate the service to their site to allow their foreign visitors to translate the page on the fly.
The userscript is using this script on all pages, which allows complete inline translation of pages and frames.

• The toolbar is hidden. It appears when the mouse pointer is moved in the top 4 pixels of the viewport.
• The boxes displaying the list of languages is scrollable to accommodate lower resolutions.

The target language is saved site by site in a session cookies. A default language can be set. See below in the section on how to install as a bookmarklet.

• The button "Set as default language" saves the current default target language for your translation.
• A button with the current default language serves as a shortcut to set the current target language when you've changed it (see the screenshot below).

The menu has other commands: (items are usually hidden and are all displayed here as a convenience)

• The first one now also save the choice in the script config
• The second allows to revert your choice
• You can turn off translation on all sites. A trigger will be added to the webpages to start the translation process, but no connection to the service is made if you don't click it.
• You can turn off globally while allowing for the current site. You can still allow/disallow individual sites with the first 2 commands
• You can revert translation on for all site
• The last item at the bottom ¿? , is there if the language used in the toolbar is incorrect. When clicked it selects the language used in your browser's interface and displays a list of country codes to choose from. You'll have to reload the page to take effect.
  Selecting the first item (empty) sets it back to autodetection.

If a cookie is set, it has precedence over other configurations.

• The current target language is ignored. If you change the default to another language, and then go back to a site recently visited, it will use the previous language. (the cookie was set at that time).
• If a site is set to never translate (global or site-specific), it will translate as set by the cookie.
• Cookies can be discarded either by clicking the cross icon in the toolbar ; by clicking "Show Original" ; when the browser is restarted and the session cookies are erased.

The session cookie is always set when a translation is attempted. Except for sites where cookies are blocked by configuring your browser.

The userscript contains several translations for the added buttons and menu items. Except for languages that I know, or poorly know, they are taken as-is from google translate. Forgive me for the errors.
The translations included are: french, dutch, spanish, italian, german, portuguese, japanese, chinese (simplified and traditionnal).

If the website that you want to translate is configured to block inline script, the translation won't work. Parts of google translate scripts will be blocked.

If you encounter any problem when running it in older browsers, feel free to contact me.

For more userscripts, styles, extensions, tips, ..., visit my programming page.