One of the best ways to reach out to family, friends, and strangers is through Instagram. However, if you want to share a video with someone on the platform, you’ll need to know how to post a YouTube video on Instagram. So, in this article, we’ll show you how to post a YouTube video on Instagram using either your mobile device or desktop computer. How to Post a YouTube Video on Instagram From Your Smartphone Using a smartphone to post a YouTube video on Instagram isn’t as easy as it sounds.