There are lots of ways to create animated GIFs, some of them easier to do than others. Although it’s still far behind behemoths like imgur, Giphy is turning into a popular option to search for and posts GIFs. Its web version has recently added the option to create your own GIFs from the website based on either local videos or ones taken from YouTube.
The idea is to make GIFs in the shortest time possible by sacrificing features along the way so you can do the entire process in less than a minute. You can select the video from either your local drive or by adding the URL for a YouTube video. That done, you have to select the start and end points for the section of the clip that’s going to loop in your GIF and optionally add a short text to superimpose over the animation.
Once that’s done, your GIF will get its own Giphy URL that you can share or even integrate into web posts, or use the resulting GIF exclusively for your purposes by extracting its location from the web address. Giphy also includes the possibility to create slideshows linking a bunch of different animations in a row. Even still, if you want more control over your creations there are more elaborate tools like Cinemagram for Android or Free Video GIF Converter for Windows.