GIF file is bigger than MP4 file?

Same problem, but I've created these many times in Adobe Express with no issues. I've resized the images and frame size and just have a few simple animations. Nothing works. It still changes an under 1MB file to a 12MB one when converting to gif. This is to insert into MailChimp - a 10MB upload limit.

There is still no answer to the original question. I have the same issue and it bugs me, too. But you can go to a free, online gif making service like https://giphy.com/create/gifmaker or any other one out there, and upload your video. It exports as a gif for you, which you can then download. They are a much smaller size. My Samsung S9 can also make a gif from a video on the phone.

Gif color support is very poor and its encoding technology is very old.  Mp4 video encoding use much newer technologies and supports color better and also support audio. Video  Players are also much more advanced  then image display application that  display image encoded with old image technology.  If you have an MP4 files why do you want to make an animated gif from it.  You loose color and sound and the file may be larger than the MP4 file and may need to be fully transferred across the web before it can be displayed. Where the MP4 file can be streamed across the web and be displayed as it is being transferred across the web and will have better color than an animated GIF and can also have sound. All Web browsers I belie support mp4 players.

To reduce file size, reduce number of frames, height and width.  To give you an example, this lively animated gif is 200 x 200px, 185 frames and just 215 KB.