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Video checker for Reels, TikTok and Shorts

Check a video’s length, shape, resolution and file size against nine networks, in their apps and through their APIs. Free; nothing is uploaded.

By Mellow · Updated

Check your video

Example, not your file: a 45-second 1080 × 1920 MP4 of 38 MB. Choose a video to check your own.
45 secondslength
1080 × 1920pixels
9:16vertical
38 MBMP4

Example. In the networks’ own apps it fits every network that publishes a limit. Through Mellow Hub it fits every network whose API publishes one.

  1. Instagram Reels

    In Instagram’s app

    Fits

    up to 20 minutes · size not published · 1.91:1 to 9:16 · at least 720 pixels

    At least 30 frames per second.

    Instagram Help Center: Record a reel on Instagram · Instagram Help Center: Reel size and aspect ratios · Meta for Developers: Instagram Graph API, IG User media (reel specifications)

    Through Mellow Hub

    Fits

    Instagram’s API: 3 seconds to 15 minutes · up to 300 MB · 0.01:1 to 10:1 · up to 1920 pixels wide · MP4 or MOV

    HEVC or H.264, 23 to 60 frames per second, up to 25 Mbps. Before sending, Mellow Hub checks that Instagram takes a video and a reel is exactly one video. It does not measure the file: Instagram’s API does, when it fetches it.

    Meta for Developers: Instagram Graph API, IG User media (reel specifications)

  2. TikTok

    In TikTok’s app

    Fits

    up to 60 minutes · size not published

    Recorded in the app, a video stops at 10 minutes. On TikTok’s website: up to 30 minutes and under 10 GB, as MP4 or WebM of at least 720 × 1280.

    TikTok Help Center: Camera tools, video length · TikTok Help Center: Tools for creators, uploading in TikTok Studio on the web · TikTok Ads Manager: In-Feed ads specifications

    Through Mellow Hub

    Fits

    TikTok’s API: up to 3 minutes, or 10 minutes for some accounts · up to 4 GB · 360 to 4096 pixels each way · MP4, WebM or MOV

    H.264 recommended; H.265, VP8 and VP9 work too. 23 to 60 frames per second. Before sending, Mellow Hub checks that TikTok takes a video. It does not measure the file: TikTok’s API does, when it fetches it.

    TikTok for Developers: Content Posting API, media transfer guide · TikTok Ads Manager: In-Feed ads specifications

  3. YouTube Shorts

    In YouTube’s app

    Fits

    up to 15 minutes, or 12 hours for some accounts · up to 256 GB

    YouTube Help: Understand three-minute YouTube Shorts · YouTube Help: Upload videos longer than 15 minutes

    Through Mellow Hub

    Fits

    YouTube’s API: length not published · up to 256 GB

    The API takes any video type and names no length of its own. Before sending, Mellow Hub checks that YouTube takes a video and a title is given, up to 100 characters. It does not measure the file: YouTube’s API does, when it fetches it.

    YouTube Data API: Videos: insert · YouTube Help: Understand three-minute YouTube Shorts

  4. Facebook Reels

    In Facebook’s app

    Fits

    any length · size not published · any shape

    Facebook shares every video as a reel, whatever its length or shape.

    Facebook Help Center: Create a reel on Facebook

    Through Mellow Hub

    Fits

    Facebook’s Reels API: 3 to 90 seconds · size not published · at least 540 × 960

    MP4 recommended, 24 to 60 frames per second. A Page can publish 30 reels through the API in any 24 hours. Before sending, Mellow Hub checks that Facebook takes a video and a reel is exactly one video. It does not measure the file: Facebook’s Reels API does, when it fetches it.

    Meta for Developers: Reels Publishing API, video specifications

  5. X

    In X’s app

    Fits

    up to 140 seconds, or 4 hours for some accounts · up to 512 MB, or 16 GB for some accounts

    X Help Center: How to share and watch videos on X

    Through Mellow Hub

    Fits

    X’s API: 0.5 seconds to 20 minutes, or 125 minutes for some accounts · up to 8 GB, or 16 GB for some accounts · 1:3 to 3:1

    60 frames per second or less; H.264 recommended. X’s developer page says its limits match the app, while its Help Center gives 140 seconds without Premium. Before sending, Mellow Hub checks that X takes a video. It does not measure the file: X’s API does, when it fetches it.

    X Developer Platform: media upload best practices

  6. LinkedIn

    In LinkedIn’s app

    Fits

    3 seconds to 15 minutes · up to 5 GB · at least 75 KB · 1:2.4 to 2.4:1 · 256 × 144 to 4096 × 2304 · MP4, MOV, WebM, AVI, MKV, WMV, MPEG and a few others

    2 seconds is enough from the phone app; 10 to 60 frames per second.

    LinkedIn Help: Video sharing troubleshooting (video requirements)

    Through Mellow Hub

    Fits

    LinkedIn’s API: 3 seconds to 30 minutes · up to 500 MB · at least 75 KB · MP4

    Before sending, Mellow Hub checks that LinkedIn takes a video and text is given, up to 3,000 characters. It does not measure the file: LinkedIn’s API does, when it fetches it.

    LinkedIn API documentation on Microsoft Learn: Videos API

  7. Threads

    In Threads’ app

    No limits published

    length not published · size not published

    Threads’ help pages give no length or size for a video.

    Instagram Help Center: Your Threads posts · Meta for Developers: Threads API overview, media specifications

    Through Mellow Hub

    Fits

    Threads’ API: up to 5 minutes · up to 1 GB · 0.01:1 to 10:1 · up to 1920 pixels wide · MOV or MP4

    HEVC or H.264, 23 to 60 frames per second. Before sending, Mellow Hub checks that Threads takes a video. It does not measure the file: Threads’ API does, when it fetches it.

    Meta for Developers: Threads API overview, media specifications

  8. Bluesky

    In Bluesky’s app

    Fits

    up to 10 minutes · up to 300 MB

    Bluesky’s own account on Bluesky: the video update of 25 August 2026

    Through Mellow Hub

    No limits published

    Bluesky’s API: length not published · size not published

    Bluesky’s developer documentation gives no length or size. An account Bluesky hosts needs a verified email before it uploads video, and Bluesky limits videos a day without saying how many. Before sending, Mellow Hub checks that Bluesky takes a video and text is given, up to 300 characters. It does not measure the file: Bluesky’s API does, when it fetches it.

    Bluesky documentation: Uploading video

  9. Pinterest

    In Pinterest’s app

    Fits

    4 seconds to 5 minutes · size not published · MP4 or M4V, and MOV from the phone apps

    H.264 or H.265.

    Pinterest Help: Review Pin specs

    Through Mellow Hub

    Fits

    Pinterest’s API: 4 seconds to 5 minutes · size not published · MP4, MOV or M4V

    Pinterest’s Pin specs apply to every Pin; its developer guide adds that a video Pin needs a cover image. Before sending, Mellow Hub checks that Pinterest takes a video and a cover image is attached. It does not measure the file: Pinterest’s API does, when it fetches it.

    Pinterest Help: Review Pin specs · Pinterest Developers: Create boards and Pins (video Pins)

A browser does not report a video’s codec or frame rate, so those are not checked; each network’s notes say what it asks for. Every limit links to the network’s own page, read on 7 October 2026.

Opens Mellow Hub. Signing up and connecting your accounts are free; publishing starts with a 7-day free trial. What you made here waits in this browser and goes into your first post, which you can change before anything is sent.

Will your video fit Reels, TikTok and Shorts?

A vertical 9:16 MP4 at 1080 × 1920, between 3 seconds and 3 minutes long and under 300 MB, fits all three, in their apps and through their APIs: YouTube counts it as a Short, every creator can post it through TikTok’s API, and it stays inside the 3 minutes past which Instagram stops recommending Reels to new audiences. The apps take longer videos, Instagram up to 20 minutes and TikTok up to 60 minutes, but the APIs that schedulers use stop sooner: Instagram’s at 15 minutes, TikTok’s at 10 minutes for the creators allowed the most, and Facebook’s Reels API at 90 seconds. Choose a video above to check it against all nine networks at once; it never leaves your device.

The limits, network by network

NetworkFills the screenIn its appThrough its API, as schedulers and Mellow Hub post
Instagram Reels9:16
Instagram Graph API, IG User media (reel specifications)		up to 20 minutes · size not published · 1.91:1 to 9:16 · at least 720 pixels
Record a reel on Instagram · Reel size and aspect ratios		3 seconds to 15 minutes · up to 300 MB · 0.01:1 to 10:1 · up to 1920 pixels wide · MP4 or MOV
Instagram Graph API, IG User media (reel specifications)
TikTok9:16
In-Feed ads specifications		up to 60 minutes · size not published
Camera tools, video length · Tools for creators, uploading in TikTok Studio on the web		up to 3 minutes, or 10 minutes for some accounts · up to 4 GB · 360 to 4096 pixels each way · MP4, WebM or MOV
Content Posting API, media transfer guide
YouTube ShortsSquare or vertical, up to 3 minutes: a Short
Understand three-minute YouTube Shorts		up to 15 minutes, or 12 hours for some accounts · up to 256 GB
Understand three-minute YouTube Shorts · Upload videos longer than 15 minutes		length not published · up to 256 GB
Videos: insert
Facebook Reels9:16
Reels Publishing API, video specifications		any length · size not published · any shape
Create a reel on Facebook		3 to 90 seconds · size not published · at least 540 × 960
Reels Publishing API, video specifications
XNot publishedup to 140 seconds, or 4 hours for some accounts · up to 512 MB, or 16 GB for some accounts
How to share and watch videos on X		0.5 seconds to 20 minutes, or 125 minutes for some accounts · up to 8 GB, or 16 GB for some accounts · 1:3 to 3:1
media upload best practices
LinkedInNot published3 seconds to 15 minutes · up to 5 GB · at least 75 KB · 1:2.4 to 2.4:1 · 256 × 144 to 4096 × 2304 · MP4, MOV, WebM, AVI, MKV, WMV, MPEG and a few others
Video sharing troubleshooting (video requirements)		3 seconds to 30 minutes · up to 500 MB · at least 75 KB · MP4
Videos API
Threads9:16
Threads API overview, media specifications		length not published · size not published
Your Threads posts		up to 5 minutes · up to 1 GB · 0.01:1 to 10:1 · up to 1920 pixels wide · MOV or MP4
Threads API overview, media specifications
BlueskyNot publishedup to 10 minutes · up to 300 MB
the video update of 25 August 2026		length not published · size not published
Uploading video
Pinterest9:16
Review Pin specs		4 seconds to 5 minutes · size not published · MP4 or M4V, and MOV from the phone apps
Review Pin specs		4 seconds to 5 minutes · size not published · MP4, MOV or M4V
Review Pin specs · Create boards and Pins (video Pins)

Every figure is from the network’s own page, read on 7 October 2026; the sources are listed at the end. Where a page gives no figure, the table says “not published” rather than borrowing one. Two networks’ pages need a word. X’s Help Center gives 140 seconds and 512 MB for accounts without Premium, while its developer page gives 20 minutes and 8 GB and says the limits match the app; the checker shows each where it belongs. TikTok’s help names no shape, so the 9:16 here is from TikTok’s specifications for In-Feed ads.

Why the app and the API differ, and what Mellow Hub checks

Every scheduling tool publishes through each network’s API, and the APIs are narrower than the apps: Instagram’s stops at 15 minutes where its app takes 20 minutes, and Facebook’s Reels API at 90 seconds where Facebook takes any length. A video that is too long for the API has to be posted from the app.

Mellow Hub publishes through the same APIs. Before it sends a video it checks what can be known without the file: that each network takes a video in that post, the title YouTube requires (up to 100 characters), the text LinkedIn and Bluesky require, the cover a Pinterest video needs, and that an Instagram or Facebook reel is exactly one video. It does not download the file to measure it; each network’s API judges length, size and shape when it fetches it. That is why the checker’s “Through Mellow Hub” column shows each API’s limits.

Getting one video past every network

  • Shoot and export vertical 9:16. 1080 × 1920 is the size Facebook’s Reels API and Pinterest recommend, above Instagram’s 720 pixels and the 360 pixels TikTok’s API takes at least.
  • Mind the shortest ceiling you post to. Facebook Reels through an API take 3 to 90 seconds; a YouTube Short is up to 3 minutes; every TikTok creator can post 3 minutes through the API.
  • Keep the file under 300 MB if it goes to Instagram through an API: the smallest ceiling among the APIs that publish one. LinkedIn’s API takes 500 MB.
  • Export MP4 with H.264. Every network here that names a container or codec takes or recommends it. The checker cannot read a video’s codec or frame rate, so check those in your editor against each network’s notes.
  • Keep words and faces off the edges. The apps lay their buttons and captions over a vertical video; the safe zone checker shows where.

Questions

How long can a Reel, a TikTok and a YouTube Short be?

In the apps: Instagram Reels up to 20 minutes, though Instagram doesn’t recommend Reels over 3 minutes to new audiences; TikTok up to 60 minutes when you upload in its app; and YouTube counts a square or vertical video of up to 3 minutes as a Short. Through their APIs, which schedulers use: Instagram 3 seconds to 15 minutes, and TikTok up to 3 minutes for every creator and 10 minutes for some.

Why would a scheduler refuse a video the app takes?

Because every scheduler publishes through the network’s API, and the APIs are narrower than the apps. Instagram’s app takes 20 minutes, its API 15 minutes and 300 MB; TikTok’s app 60 minutes, its API 10 minutes; Facebook takes a reel of any length, its Reels API 3 to 90 seconds. A longer video has to be posted from the app.

What size should a vertical video be?

9:16: Instagram, TikTok, Facebook, Threads and Pinterest name it for a video that fills the screen, TikTok in its specifications for In-Feed ads. Facebook’s Reels API and Pinterest recommend 1080 × 1920; Facebook’s Reels API takes no less than 540 × 960, and Instagram asks for at least 720 pixels. YouTube counts any square or vertical video of up to 3 minutes as a Short.

What is the largest video file each network takes?

Through the APIs: Instagram 300 MB, TikTok 4 GB, YouTube 256 GB, X 8 GB (16 GB for some accounts), LinkedIn 500 MB and Threads 1 GB; Facebook, Bluesky and Pinterest publish no figure for theirs. In the apps: YouTube 256 GB, X 512 MB (16 GB for some accounts), LinkedIn 5 GB and Bluesky 300 MB; Instagram, TikTok, Facebook, Threads and Pinterest publish no figure.

Is my video uploaded anywhere?

No. Your browser opens the file on this page and reads its length, pixels, size and type; the video is not sent to Mellow or anyone else. If you press the button to schedule it, it is kept in this browser until you are signed in to Mellow Hub, and it goes into your first post only when you use it there.

Why does the checker say “not published” for some networks?

Because that network’s own pages, read on 7 October 2026, give no figure, and the checker does not fill the gap with somebody else’s estimate. Threads’ help gives no length or size for a video, and Bluesky’s developer documentation none for uploads through its API. Facebook is different: it says its reels take any length, so its app is checked as such.

Sources

What Mellow Hub checks before sending is read from its own registry of network rules, the one its validator enforces.

Send one video to Reels, TikTok and Shorts at once

Mellow Hub publishes one video to Instagram, TikTok, YouTube, Facebook, X, LinkedIn, Threads, Bluesky and Pinterest in one post, with a caption for each network where you want one. Before anything is sent it checks what it can know without the file, such as YouTube’s required title and a Pinterest video’s cover; each network’s API judges the file itself when it fetches it, which is why the checker shows those limits. See the rules for every network.

Schedule on Instagram and TikTok

See what each network accepts in Mellow Hub

This tool is free and needs no account. Mellow Hub is paid, after a 7-day free trial, and publishes only what you, or an assistant you have authorised, send or schedule.

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  • YouTube thumbnail tester: See a thumbnail in YouTube’s home feed, search and sidebar at their real sizes, then export it at 1280×720 under 2 MB.
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  • Social media post checker: Check caption, title and media count against Mellow Hub’s input rules for each destination.
  • Reels and Shorts safe zone checker: See where Instagram Reels and YouTube Shorts cover a vertical video with their buttons and captions, from the figures Meta and Google publish, and download the template.
  • Reels and Shorts cover maker: Pick a frame from your video, add a title, see how the cover sits in the profile grid and export it at 1080 × 1920.
  • Social media image resizer: Crop one picture to every network’s post, story and cover sizes at once and download them together.
  • Hashtag counter: Count the hashtags and mentions in a caption against each network’s limit, drop duplicates and copy a clean set.
  • Instagram font generator: Turn words into bold, italic, script and other Unicode letter styles for an Instagram bio or caption, and see what styled letters cost screen readers, search and hashtags.

All free tools · Answers about posting and scheduling

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