Feed posts. To start, Instagram feed posts support video aspect ratios in 16:9, 4:5, and 1:1 with varying pixel sizes.
But just because a platform allows you to post in different sizes, it doesn’t mean you should increase and decrease without discernment. No matter what, the platform will automatically adjust the size to fit those ratios.
Instagram is an app geared toward mobile use as opposed to a desktop computer or a TV and feed posts will not flip horizontally. Because of this, it’s best to post videos in a 4:5 ratio at 1080 × 1350 for optimal viewing, or at least go with a 1:1 square ratio at 1080 × 1080.
Stories, Reels, and Instagram live. There’s less flexibility when it comes to stories, They all play in a vertical video format of 9:16 and while you can adjust your stories down to 1080 × 608 and there are hacks to make them horizontal, uploading at 1080 × 1920 is best for optimal viewing without borders.
Reels and Instagram live are both locked at the 9:16 ratio and at 1080 × 1920.
IGTV. Things get a little more complex when trying to figure out what ratio to use for Instagram’s video app that allows for longer videos outside of the feed. It’s again optimal to opt for the 9:16 ratio and at 1080 × 1920 for mobile viewing.
However, if your video was originally shot for another platform like YouTube geared for 16:9 at 1920 × 1080, you can still post the video in this format via IGTV. It’s the one place on Instagram where a viewer can flip the clip horizontally, but you may want to put a message indicating that viewers rotate the video.
With IGTV you also need to be aware of the preview – the first 15 seconds – that plays in a viewer’s feed at 1080 × 1350. Fortunately, Instagram allows you to align the video, so you can show exactly what you want.
You can also upload an image instead for the preview, and if you choose this option, opt for the 1080 × 1350 resolution.
Last, the preview in your profile grid will show at 1:1 and at 1080 × 1080. For this preview, you can either take a snapshot from the video or upload it from your camera roll.
Carousel. Like videos in your feed, carousel posts offer portrait (1080 × 1350), landscape (1080 × 608), or square (1080 × 1080) viewing. But once you select a ratio and size for the first video, all other videos will crop and adjust to the same ratio and size and maintain that ratio for the rest of the sequence.
Instagram recommends a 1:1 ratio for all carousel videos.