How to pause GIF animation at specific frame

The simplest way to do it is play your gif animation in mplayer

Open your gif file in mplayer using following command

  mplayer -loop 0  -speed 0.2 your_gif

Here

-loop 0 means it will run your gif image untill you are not closing it and
-speed 0.2 means it will decrease the animation speed to 20%.

You can pause your animation by pressing the Space button .
mplayer will also show the frame information of your running gif in terminal.

I guess you want to pause it to grab a specific frame and save it as a stand-alone image.

Open it with the gimp, it will load each frame as a separate layer. You can then delete or make invisible all the frames/layers except for the one you want, and export the image in any format supported by gimp.

Although mplayer is indeed a simple way just to pause GIF animation and perhaps make a screenshot of a particular frame, it seems thas mplayer does not allow to navigate between frames. A tool gifview (provided by gifsicle package in Ubuntu) does a great job to provide fine-grain control over gif viewing. See the (very short) manpage for gifview for corresponding shortcuts.

Make sure you disable the optimized mode with u. Otherwise, only diffs between frames will be shown and one can have an impression that the tool does not work properly.