Twitter added support for GIFs in February this year, but there was a limit for GOF size. Now, Twitter has expanded the limit to 15 MB. So, you can now share a GIF of size up to 15 MB on Twitter.
Also: Twitter Now Supports Animated GIFs
Initially, the size limit for GIF was 5 MB. For mobile, Twitter still has same 5MB limit. This increase in size limit is only for web. Photo upload limit remains the same. So, you can only upload photos of up to 5MB.
We are not sure why this increase in size limit. No one is going to upload this much of large GIF. Twitter has also updated its posting support page to reflect new size limit.
Twitter has also partnered with Giphy and Riffsy in order to bring GIF support. So, we can assume that Twitter took this step to avoid any sizing issues if occur in future.
There is no word when this GIF support will come to Tweetdeck.
