Nopes. Nuffin. Rated 1 out of 5 stars

I installed this in the hope that, finally, I wouldn't have to navigate two context menus to change between english and german dictionaries.
This addon, however, only adds buttons. One that gives the abbreviated name of the active dictionary, the other with a drop-down men.
If I click the one that lists the dictionary name, the name that is listed changes. Yay.
The active dictionary, meanwhile, does not change. Nay.
The other, with the drop down, won't list anything other than "English/United States". Even though I have three dictionaries installed. Re-installing one of the German dictionaries and repeatedly restarting Firefox did not change anything, at all.
This addon was a frustrating waste of time.

This user has a previous review of this add-on.

Any chance to port this addon to Postbox ? Rated 5 out of 5 stars

Would be great to use it on postbox, and seems to be easy to port addons from thunderbird.

Rarely works as intented Rated 1 out of 5 stars

This addon is supposed to do something rather simple, yet it doesn't do it most of the time.

Rated 4 out of 5 stars

Tested from the status bar: working well. But it's not a dictionary switcher, it's a local switcher.

This user has a previous review of this add-on.

Wenn es funzt ists klasse! 90% der letzten Jahre funktioniert ed aber nicht. Rated 1 out of 5 stars

Wenn es funzt ists klasse! 90% der letzten Jahre funktioniert ed aber nicht. Keine Ahnung was los ist. Es wird zwar anscheinend ständig aktualisiert, aber in meinem FF aufm Mac gehts nicht.

Doesn't work Rated 1 out of 5 stars

For me it's an essential requirement to switch languages automatically like it's default with Chrome, but it doesn't work.

Work well BUT sadly DON'T work with E10 Rated 3 out of 5 stars

Produce lot of "unsafe CPOW usage" when E10 enabled.

This user has a previous review of this add-on.

No use contacting author, addon defunct Rated 1 out of 5 stars

Tried contacting author pr email as he requests instead of review, but since he doesnt seem to answer to that, then its no use to use his email.

Actual review : Hoped to use this addon for US and DA language, but DA localizations has been removed because they are out of date. So I can switch between US and US and then the addon lost it usefullness.
Tried to contact author for any solutions but no answer.

Needs to be "verified" Rated 3 out of 5 stars

Apparently, the add-on needs to be "verified". Firefox complains that it will be disabled after next restart. No idea why?
It's a pity, since it's a must-have addon for users that use several languages :(

Simply indispensable Rated 5 out of 5 stars

Could not do without it. So when it stopped working I was ready to try and fix it.
Until I realized the bug was likely linked to my firefox syncing of deprecated variables for the add-on.

What I had to do is go to about:config and set
Now it's responsive again and works as intended.
I saw in the reviews here that we have to set extensions.dictionary-switcher.autodetect;true
but I believe this is an old variable no longer used by the add-on and seems to have no effect on the add-on at all.

At any rate this is the most underrated add-on for firefox, hands down. :D

Props to developer/maintainer, even though it could have less bugs. Thanks a million.

This user has a previous review of this add-on.

works perfect with Thunderbird Rated 5 out of 5 stars

Finally I found a version that works with my Thunderbird (38.6.0) and it´s great. It automatically switches between the three installed languages after typing in not more than five words!

Ne fonctionne toujours pas Rated 1 out of 5 stars

Ne fonctionne toujours pas sur Firefox 43.0.4

Not working Rated 1 out of 5 stars

it never changes directory, i have 2 languages i use, English and -Danish, its hella annoying to have to change all the time, when i write, this addon never works :(
im on newest Firefox 44.0

Great, but needs improving Rated 3 out of 5 stars

Works great, but have some issues.
Sometimes it shows wrong language (different is chosen for spellchecking).
Sometimes detects wrong language without a reason and don't want to correct it even after putting a lot of text.
Manually changing language always locks the choice for that site.
Auto-detecting sometimes stops firefox responding for few seconds.
It should have icon that will change depending on chosen language.
Toolbar button is inconvenient, looks ugly (like it is pressed) and change its width with every language change.
After some time of using automatic detection starts to go insane.
I hope it will be improved soon, that I would use it completely.

Unfortunately doesn't work with the current Firefox Rated 1 out of 5 stars

which is sad

Essential add-on, just needs updating Rated 3 out of 5 stars

This is such an essential add-on for anyone typing in more than one language in Firefox, unfortunately, it hasn't been updated in a while and doesn't work well with e.g. Gmail, it can freeze the whole Firefox for short amounts of time, etc. But it's a really good idea.

Rated 3 out of 5 stars

Sadly not compatible with Thunderbird 38 any more, since in that version the spell check language in the compose windows has been decoupled from the preference.

Dictionary Switcher has to manually be edited to work! Rated 5 out of 5 stars

To have this to work in Firefox:
You have to manually go into about:config and changed - extensions.dictionary-switcher.autodetect to true. But some times I have to get in to about:config again to switch in on, off and on again to work, even if it's "on" in extensions.dictionary-switcher.autodetect. Then it work again to switches languages.

To do this on Thunderbird:

Go in to in Thunderbird: Options>Advanced>Config Editor set this as 'true'

I hope they will fix this. Also autodetect as I write does not work. I'm on Windows 10, and with a clean installed OS, and only two language installed in Firefox.

This switcher should had been an included part of Firefox and Thunderbird.

Rated 5 out of 5 stars

Funktioniert nun endlich mit der neuen Generation von Wörterbüchern (Stichwort „restartless“) – vielen Dank für das Update!

Worked once Rated 4 out of 5 stars

I know it worked once but now i had the problem that it turned to english but i couldnt manually change it back. Eventually it turned back later alone but now im searching the button to change it. Its nowhere to found. I checked the dialogs with firefox, opened all bars in there and i dont see it. Whats up?