TL;DR: To set up the Convert Video to GIF tool, download the “Convert Video to GIF” Service from this GitHub Repository and follow the install instructions in the README.

Last weekend, I was working on making a Big List of Naughty Strings for user-data testing. (now up to 4,000+ GitHub Stars!) For the README, I needed a visual example to demonstrate why testing bad strings is important. I easily made a video of an internal server error on Twitter using Quicktime and its Screen Recording feature to record, crop, and trim the event. But videos cannot render on GitHub; only GIFs can. And ideally I would not include a 807KB file everytime a user loads the GitHub page.

Websites that offer online Video-to-GIF converters are often seedy and create low quality, low frame-rate GIFs. I did some research and eventually I tried Gifrocket, a recently-released tool that promises effortless drag-and-drop video-to-GIF-conversion.

The quality is not terrible, although the ghosting is weird, and the framerate is choppy when the cursor moves. Unfortunately, I can’t optimize any settings. File Size is 534KB, which is a slight compression but not great.

As a result, I gave MoviePy, a Python API for manipulating videos another try, as I had used it for other posts on this blog to good success. However, I had to shrink them significantly to keep load times down; something I would prefer not to do with my internal server error GIF in order to maximize readability. On the blog post announcing GIF support, the core developer relayed an interesting comment from another reader that “mencoder/ImageMagick/gifsickle is a winning trio for Gif making.”

I’ve heard of ImageMagick before: it’s the tool that drives nearly all image manipulation on the internet (it’s also what Gifrocket uses). But what was mencoder and gifsickle?

Some searching led to this 2012 Reddit comment in the /r/reactiongifs subreddit. That’s where everything clicked.

Shell Games

The linked Reddit post conveiently uses the same three tools by the commenter on MoviePy. I ran the terminal commands on my video, with a little tweaking.

The first command uses the mencoder functionality of mplayer to render each frame of the video to PNGs:

mplayer -ao null -vo png:z=1:outdir=gif -vf scale=608:454

I set the size to a width of 608px since it was exactly 50% of the width of the raw video, but I could set it to whatever I want, although it would be ideal to keep the aspect ratio the same.

The second command uses ImageMagick’s famously robust convert comand to convert the rendered frames in to a GIF, with two optimization passes for lower file size and ~16.6ms delay, which is equivalent to 60 frames per second.

convert +repage -fuzz 1.6% -delay 1.7 -loop 0 gif/*.png -layers OptimizePlus -layers OptimizeTransparency Almost.gif

This results in a 156KB image; much, much better than the 534KB from Gifrocket, and at a much higher framerate too.

Lastly, the GIF is further optimized with gifsicle, which also limits the color pallete to 256 colors for even lower file size.

gifsicle -O3 --colors 256 Almost.gif > Done.gif

This results in a 107KB KB, a 31% savings over the already-optimized GIF, without any discernable loss! Here is the final result:

Much, much better. No ghosting, 60 FPS, 1/8th of the original video file size, and 1/5th of the file size of the Gifrocket GIF!

Then I realized; aside from the output GIF resolution in from mencoder, the terminal commands for making GIFs are very generic. What if I could easily automate these steps for any video on my Mac?

Full Automatic

I decided to make a OS X Service, which can be used to automate actions for a specified file type in the form of a right-click menu option. Services can be created using Automator, which is included in all OS X installations. In my case, I want to create a Service for movie files; and when the Service runs, it should Run a Shell Script with the above three commands.

After writing the script, which incorporates a maximium GIF width of 480px and will resize larger GIFs to that size while maintaining the aspect ratio, the Service is complete and I can right-click any Movie file and get an optimized GIF!

Yes, even a 41.6MB 720p video file, which most GIF converter sites would never let you upload, becomes a relatively reasonable 1.3MB GIF!

This approach also has an unexpected benefit; the script support batch conversion, meaning you can convert as many videos as you want at the same time!

As usual, my code is open sourced on GitHub with a MIT license, with instructions on how to set up the tool. The repository also includes two bonus utilities; a Shell Script to run the conversion from the command line and an Application which prompts you for movie files instead of needing to right-click. Install the three command-line applications and convert away! Or fork the repository and make an even better Video-to-GIF conversion tool!


Max Woolf (@minimaxir) is a Software QA Engineer living and working in the San Francisco Bay Area for over 4 years and a 2012 Carnegie Mellon University graduate in Business Administration.

In his spare time, Max uses Python to gather data from public APIs and ggplot2 to make pretty charts from that data.

You can learn more about Max here, or view his portfolio here.