IMHO still the best Rated 5 out of 5 stars

If you need a password manager solution that will work across all platforms (including smart phones), all OSes, all browsers and that is more than affordable (many users can use it for free and even a premium account is very affordable compared to competitor prices), LP is for you. Storing passwords on servers is always risky, but using poor passwords or the same passwords everywhere is much, much, much more risky today!

Regarding all the comments about 4.x: 4.x is still not stable, it's an alpha version. So it has bugs, it may not always work correctly, it may be slow, functionality may be missing, it may fail completely if there is a browser update. That's what alpha means. Seriously, how can you install an alpha version and then make complains like that and give poor ratings? That's also why there is no autoupdate to 4.x Users have to decide themselves if they want to test alpha versions. Once 4.x is considered stable enough to replace 3.x, there will be an autoupdate for sure. Right now you are not missing anything if you stay with 3.x (the biggest changes are the new UI look so far).

As amnesia mentioned, download from LastPass website! Rated 1 out of 5 stars

I really like this add on, but since Mozilla is still not able to quickly test and release add on updates, I've been using the old version all this time. Unfortunately the new version is very much slower, though I like new look.

Thanks amnesia for the mention, now I'm running the latest 4a.

@mecki78: There's a new vulnerability, that can steal all your passwords with version 3.x !!

So inform yourself befor spreading misinformation about the biggest change being "the new UI look so far"

This user has 2 previous reviews of this add-on.

Unusable right now Rated 1 out of 5 stars

The latest version (4.1.21a) doesn't work with Firefox 47.0.1 - clicking on Preferences does nothing. Given that previous versions have a security flaw that allows sites to steal your passwords, right now this is an add-on that must be avoided.

Get the addon from the Lastpass website. It is more updated than the version on Firefox addon repository. Rated 3 out of 5 stars

Despite both the Lastpass website and Mozilla website state the addon is at version 4.0, the version on the Lastpass website has the new UI, whereas the one from here is the old version. Love Lastpass, just be warned, and hope it will be fixed.

Stay with version 3 Rated 3 out of 5 stars

I agree with the others, the new version 4 is not very well coded. It's slow, not easy to use and we waste time on a few operations. And sometimes it just bugs completely and I have access to nothing except white pages.
At the end I've been running 3.3.1 and I won't change for a while.
Ps: I'm also a paid user, but that doesn't change anything.

Gone downhill Rated 2 out of 5 stars

I love Lastpass but since LogMeIn bought it it's becoming worse and worse. First they made a shitty new UI, now they won't even fix the blank forms and email/pw forms not saving issues, last but not least it's making Firefox SO SLOW! I hate not having the cloud saving feature, but I am contemplating the move to Keepass.

Love Version3, but... Rated 1 out of 5 stars

I'm a paid user, and I love Version3. BUT, the UI for version 4 is crap, cannot edit anything, it's unusable.

Very Useful Rated 5 out of 5 stars

I use it in my PC and my laptop and synchronization works without any problem.
I save a lot of time tiping keywords and user names.

New UI is Crap Rated 2 out of 5 stars

Switching from Chrome to Firefox. In Chrome you could toggle the older interface, on Firefox's LastPass you can't.

LastPass, your new UI is complete crap. It is not designed for a desktop. This isn't Android. Redo it.

Horrible Performance Rated 1 out of 5 stars

How does this get so many good reviews? I may have corrupted some settings in Firefox somehow, but I get horrible performance in Firefox when I have this add-on enabled.

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

Love it! Rated 5 out of 5 stars

I've never written a review for an Add-on, but Lastpass has changed my life. That's not even an exaggeration. The Firefox Add-on works as promised for me, and adds to the seamless integration of convenient password management across devices. Thanks for a great product Lastpass!

Rated 1 out of 5 stars

No electrolysis support and about:performance indicates that LastPass is severely slowing down Firefox

Had to stop using. No electrolysis support. Rated 1 out of 5 stars

No electrolysis support = goodbye.

With E10s enabled, it constantly freezes, doesn't connect to the servers.

Nope Rated 1 out of 5 stars

Support is useless with their canned robotic auto responses and although they have a forum for feature requests, it's just giving false hope and they don't actually care.

Why the heck is dealing with ports like not native? Because it's badly written, that's why.

Old and dated Rated 2 out of 5 stars

This addon looks very old and dated. The hover menus often appear in the wrong place (across the screen) and sometimes doesn't work at all. Even things like viewing the sites just opens a blank page and sits there saying its waiting for the page to load.

slow down the browser Rated 3 out of 5 stars

It took me a while before finding out that this addon is the culprit for slowing down the entire browser which needless to say I'm deeply disappointed.
PS:V4 is much better, strongly suggesting using dev channel

This user has 2 previous reviews of this add-on.

this crap slow down firefox startup time a lot Rated 1 out of 5 stars

this crap slow down firefox startup time a lot

Indispensable! Rated 5 out of 5 stars

Siempre que he de instalar Firefox en un nuevo PC, mi primer complemento es Lastpass seguido de Xmarks. Excelentes e indispensables los dos.

Outdated Rated 4 out of 5 stars

I love the LastPass BUT the version on mozilla is outdated. LastPass 4 is out and you should get it from the official LastPass website.

Plz sign this app Rated 1 out of 5 stars

Why the heck this app doesn't get signed? I hv to look for a replacement then.
Even Keepass&Firefox is broken.
I better look for a replacement for Firefox.