But as a Mashable points out, there's actually a better way to save Instagram photos that doesn't involve cropping screenshots, and best of all, you'll get a higher quality version of the image. It takes a few extra steps, though.
Here's what you need to do:
1. Open the image you want to save on Instagram via your desktop browser (Chrome, for example). You'll have to click the time stamp so that the post appears by itself (not your whole timeline).
2. Click where it says View on your browser's top menu, followed by Developer > View Source. Note: You can also do this just by right-clicking the image and clicking View Page Source.
3. Somewhere on the long page of code is a URL to the actual image file on Instagram's server. Instead of reading through the whole thing, though, you can just search the page of "jpg" and you should come across the correct URL fairly quickly. It'll look like this (URL highlighted):