Instagram Reels size, length and format (2026)

Instagram Reels are vertical videos that play full screen, but the rules for them are spread over several pages: Instagram's Help Center for the app, its developer documentation for scheduling apps, and Meta's ad guides. This page puts the numbers in one place, as checked in October 2026, and explains the parts people most often get wrong: how long a Reel can really be, why a 4K video can fail in a scheduling app, and how covers get cropped.

Instagram Reels size and specs at a glance

The middle column is what the Instagram app accepts. The right column is what Instagram's API accepts, and that's what every scheduling app, Unisenda included, has to follow.

The best size for a Reel: 1080 × 1920

Instagram doesn't name one exact pixel size for Reels, but one size meets all of its rules: a vertical 9:16 video at 1080 × 1920 pixels. It's above the Help Center's 720-pixel minimum, it's the 9:16 shape the developer documentation recommends to avoid cropping or empty space, and it's under the 1,920-pixel width limit for videos sent by apps.

That width limit catches a lot of people out. A phone video filmed in 4K is 2,160 pixels wide even when you hold the phone upright, so Instagram's API won't take it as it is, and a scheduling app has to send a smaller copy. If you edit before posting, exporting at 1080 × 1920 avoids the problem.

Other shapes are allowed: the app takes anything from 1.91:1 (wide) to 9:16 (tall). A wide or square Reel just doesn't fill the screen. When you post from the app, you can also turn on Upload at highest quality in the menu under Media quality. Instagram notes that higher-quality uploads can take longer.

How long can an Instagram Reel be?

In the Instagram app, a Reel can be up to 20 minutes, recorded in one clip or several that add up. The same Help Center page adds a catch: Reels over 3 minutes won't be recommended to new audiences, so they mostly reach people who already follow you.

Apps that post through Instagram's API work with a different range: at least 3 seconds and at most 15 minutes. A Reel longer than 15 minutes can only be posted from the Instagram app itself.

The practical rule: keep a Reel under 3 minutes if you want it to reach new people, and under 15 minutes if you want to schedule it.

File size, frame rate and format

For Reels sent by apps, Instagram's developer documentation sets these limits:

• Up to 300 MB per video.
• 23 to 60 frames per second, though the Help Center says Reels should have at least 30.
• MP4 or MOV, with H.264 or HEVC video and AAC audio.
• A video bitrate of at most 25 Mbps.

The 300 MB limit is the one long videos hit. At 300 MB, a 3-minute Reel has room for about 13 megabits per second on average, and a 10-minute Reel for about 4. If a long Reel is too big, export it again at a lower bitrate or trim it.

If an app rejects your Reel, export it as an H.264 MP4 with AAC audio at 1080 × 1920 and 30 fps. That meets the shape, width, frame rate and format rules above; then check that the file is under 300 MB.

Instagram Reels safe zone

Instagram's interface sits on top of every Reel: your name and caption near the bottom, and the like, comment and share buttons on the right. Meta only publishes exact safe-zone numbers for ads. Its Reels ad specs suggest keeping at least 14% of the top, 35% of the bottom and 6% of each side free of text and logos.

On a 1080 × 1920 video, that's roughly the top 270 pixels, the bottom 670 pixels and 65 pixels on each side. These are guidelines for ads, not rules for regular Reels, but they're a sensible guide for any text you add to a video. To see them on a frame of your own video, use the free safe zone checker.

Covers, the grid and the feed

The cover is the still image people see before a Reel plays. In the app you can choose a frame from the video or upload an image. Instagram's Help Center recommends a cover of 420 × 654 pixels (about 1:1.56) and says that, at the moment, you can't change the cover after uploading, so pick it before you share.

Scheduling apps can send a cover too: either a frame from the video, chosen by its time (the first frame if none is set), or a JPEG image of up to 8 MB. Instagram's developer documentation recommends a 9:16 cover image and crops other shapes to the middle 9:16. When a Reel is also shared to the feed, the feed post uses the middle square of the cover.

So whatever you use, keep faces and title text in the middle of the image, where every crop keeps them. The full 9:16 frame only shows once someone opens the Reel.

Apps can also choose whether a Reel may appear in the feed as well as the Reels tab. Either way, the documentation notes, Instagram itself decides whether the Reel actually shows up in the Reels tab.

Captions, hashtags and mentions

Instagram's developer documentation allows captions of up to 2,200 characters with up to 20 @mentions. Only the first line or so shows before the "more" link, so put the point first.

Hashtags changed recently. Instagram's Help Center now says you can use up to 5 hashtags on a post. Older guides, and some of Instagram's own developer pages, still show the previous, higher limit, so go by the Help Center: pick 5 or fewer that describe the video, and your caption works in the app and in any scheduler.

What scheduling apps can and can't do

Instagram's API publishes Reels to professional accounts only, within the limits in the right-hand column above. Instagram's filters and shopping tags aren't available to apps, so add any filter in your editor before you export. For the full steps, see how to schedule Instagram posts.

How Unisenda handles Reels

Unisenda posts Reels through Instagram's API, so it follows the limits above and takes care of the fiddly parts:

• Big files. Upload videos of up to 500 MB (MP4, MOV or WebM). When Instagram accepts your file as it is, Unisenda sends the original without compressing it; when it doesn't, for example over 300 MB, Unisenda sends a sharp copy that fits.
• 4K and phone formats. Instagram doesn't accept videos wider than 1,920 pixels from apps, so for those Unisenda makes a sharp 1080p copy. Phone videos in MOV or HEVC get an H.264 MP4 copy automatically. Your original always stays in your library.
• Covers. Choose Cover to pick a frame from the video or upload an image.
• Music. Add a song from Instagram's licensed music library and set the song and video volume.
• Checks and previews. Unisenda flags what Instagram would reject before you schedule, and the phone preview shows how the vertical video will look.

You can try all of this in the demo, where nothing is ever published, and every plan starts with a 7-day free trial. Posting the same video elsewhere? See the TikTok video size guide and how to post one video to TikTok, Reels and Shorts.