This is an ancient post. At the time it was written, there weren't a lot of good choices. The need still exists, and for people with the same problem landing here, there are now good solutions available as Firefox extensions. Entering "translate" into the extensions search window returns almost 600 choices for translation in some form as of this time.
The specific requirement here is the ability to quickly translate a selected word or phrase without the need to open another tab or app, and copy and paste to get the translation. There are now many extensions that provide this ability. Most seem to be front-ends for Google Translate, since that generally does a good job with the translation, and auto-detects a huge number of languages.
The general way these work falls into several categories:
- Activation method: some use a right-click context menu entry to trigger translation, and some use a toolbar icon. The toolbar icon is a single mouse click, where the context menu requires several clicks. However, the context menu flows directly from the selection while the toolbar icon requires going somewhere away from the selection. What's best is a matter of personal preference.
- Results location: some open a new tab and take you there for the result, and some pop up a result window on the same page. Either style requires a mouse click to close it (which, in the first case, also returns you to the original page). Again, a matter of personal preference.
Many of the choices are widely used and highly rated by users, so you aren't likely to go too far wrong with any extension you choose if you check the user ratings. It's also a trivial task to load an extension and remove it if you don't like it. So try a number of different offerings and pick the one you like best.
Extensions come and go, so there's no way to know what will be around at the time you read this. A few of the current offerings (not an endorsement, just illustration to get you started):
Context menu to new tab:
Context menu to on-page popup:
- Selection Translate - For AltKey by dfromytb. Not a context menu entry, but you hold down the Alt key while making the selection and a popup window presents the results. On my system, holding the Alt key while making a selection drags the Firefox window around the screen, so using or testing this would require changing key assignments. Test for yourself.
Toolbar Icon to new tab:
- Google Translate (In Page Translate). Icon only. Claims to translate without leaving the page (on-page popup), but my test opened the selection on a new tab and took me there, so YMMV.
- See Translate Now by Geoffrey De Belie, above.
Toolbar icon to on-page pop-up: