# What Aspect Ratio, Size and Length Do TikTok, Instagram Reels and YouTube Shorts Accept?

URL: https://fulinlabs.com/blog/short-video-aspect-ratio-size-limits-2026/
Published: 2026-11-11
Product: schedulepost
Summary: Documented video requirements for TikTok, Instagram Reels, YouTube Shorts and Threads as of November 2026: aspect ratio, file size, length and format, with sources.

**A vertical 9:16 MP4 under three minutes and under 300 MB fits the documented limits of TikTok, Instagram Reels and Threads, and meets YouTube's rule for a Short.** Each platform sets its own limits, and the figures below are the ones their developer documentation states, checked on November 11, 2026. App uploads can have different limits from API uploads, so check the in-app message if something is refused.

I build [SchedulePost](https://schedulepost.fulinlabs.com), a scheduler that publishes through these APIs, so these are the limits that matter when a post is sent by a tool rather than by hand. Where a platform's documentation does not give a number, I say so instead of quoting a blog.

## What are the video requirements for each platform?

| | TikTok | Instagram Reels | YouTube Shorts | Threads |
| --- | --- | --- | --- | --- |
| Aspect ratio | Not specified in the upload guide; 9:16 is the standard vertical frame | 0.01:1 to 10:1 accepted; 9:16 recommended | Square or vertical | 0.01:1 to 10:1; 9:16 recommended |
| Length | 3 minutes for all creators; some accounts 5 or 10 | 3 seconds to 15 minutes | Up to 3 minutes | Up to 5 minutes |
| File size | Up to 4 GB | Up to 300 MB | Not stated on the Shorts help page | Up to 1 GB |
| Container | MP4 (recommended), WebM, MOV | MOV or MP4 | Not stated on the Shorts help page | MOV or MP4 |
| Video codec | H.264 recommended; H.265, VP8, VP9 | HEVC or H.264 | Not stated on the Shorts help page | HEVC or H.264 |
| Resolution | 360 to 4,096 pixels per side | Maximum width 1,920 pixels | Not stated | Maximum width 1,920 pixels |
| Frame rate | 23 to 60 fps | 23 to 60 fps | Not stated | 23 to 60 fps |

Sources: TikTok Content Posting API media transfer guide; Instagram Graph API IG User media reference (Reels); YouTube Help, "Understand three-minute YouTube Shorts"; Threads API posts documentation. Blank cells in a table like this are honest: the YouTube Shorts help page states the length and shape rule and does not publish file size or codec limits, so I do not quote any.

## What aspect ratio is best for TikTok, Reels and Shorts?

9:16. Instagram's documentation recommends it explicitly "to avoid cropping or blank space", Threads says the same, and YouTube accepts only square or vertical frames as Shorts. A 1080 by 1920 frame is the usual size. Square (1:1) and 4:5 work on some platforms but waste the full-screen frame, and a horizontal 16:9 video will not be classified as a Short.

To check a file before you upload it, the [video aspect ratio checker](https://schedulepost.fulinlabs.com/tools/aspect-ratio) reads the dimensions and tells you which platforms the format suits.

## Why is my vertical video not a YouTube Short?

YouTube's help page says a square or vertical video up to three minutes long, uploaded on or after October 15, 2024, is classified as a Short. A 9:16 video at three minutes and one second is not. Classification is automatic. The fix is to trim to three minutes or accept that it will appear as a normal video.

## What about the safe zone for captions and buttons?

Every app overlays its interface on a 9:16 video: a profile and caption at the bottom, a button column at the right. Text placed there is covered. There is no official pixel-exact number I can cite, because apps change their overlays, so treat any figure as approximate. The [safe zone checker](https://schedulepost.fulinlabs.com/tools/safe-zone-checker) lets you overlay approximate zones for Reels, TikTok and Shorts on a frame and download a template, and it runs in the browser. Keep important text well inside the frame and test on a phone.

## When is this not the right tool?

A format checker does not judge a video, only its shape. If a file fails for another reason, such as an unsupported codec, re-export it as H.264 MP4 with AAC audio and try again. If TikTok refuses a post, the cause may be your account, not the file; see [TikTok's schedule post limits](/blog/tiktok-schedule-post-time-limit-2026/) and why [a post can fail even when the file is fine](/blog/auto-publish-vs-notification-reels-schedulers-2026/). For the text side, see [caption length limits](/blog/short-video-caption-length-limits-2026/).

## Quick checklist

- Export 9:16, 1080 by 1920, MP4, H.264 video, AAC audio.
- Keep it under 300 MB and under three minutes to fit the documented limits of all three platforms.
- Keep text inside the safe zone and check it on a phone.
- Confirm the account-specific limit in TikTok, which can differ by creator.

## FAQ

### What aspect ratio should a TikTok, Reel or Short be?

9:16 (vertical, for example 1080 by 1920) is the safe choice for all three. Instagram's API accepts ratios from 0.01:1 to 10:1 but recommends 9:16 to avoid cropping or blank space. YouTube classifies only square or vertical videos of up to three minutes as Shorts.

### How long can a TikTok video be?

TikTok's developer documentation says all creators can post 3-minute videos, and some can post 5 or 10 minutes. The longest video a developer can send through the upload endpoint is 10 minutes. The limit that applies to your account is set by TikTok.

### What is the maximum file size for an Instagram Reel?

Instagram's Graph API documents 300 MB for a Reel published through the API, with a duration of 3 seconds to 15 minutes and a maximum width of 1,920 pixels. The Instagram app's own limits can differ.

### Do TikTok, Reels and Shorts need different files?

Usually not. One 9:16 MP4 with H.264 video and AAC audio, under 300 MB and under three minutes, fits the documented TikTok, Instagram and Threads API limits, and YouTube's Shorts rule (square or vertical, up to three minutes) as well; YouTube publishes no file-size or codec limit for Shorts. Where you still need care is the safe zone, because each app overlays buttons and captions in slightly different places.

### Why is my vertical video not showing as a YouTube Short?

Check its length and its upload date. YouTube classifies a square or vertical video as a Short only if it is up to three minutes long and was uploaded on or after October 15, 2024. A video over three minutes stays long-form.