Originally Posted by JosephFM

I don't think there's a frame limit. As long as they are 2mb or below you will be alright.

It says in tumblr faq that gifs should be 1mb and 500px wide but I have been making and posting gifs that reach up to 2mb with no problems.

BTW, you can also post your gifs to your twitter accounts also if you have one (I didn't know that till recently) so you get the most out of them. The limit on twitter is about 5mb I think.