Reels vs TikTok vs YouTube Shorts: Specs and Differences
Reels, TikTok and YouTube Shorts all want 9:16 vertical video, but lengths, music rules and audiences differ. Here are the 2026 specs and cross-posting tips.
Comparisons6 min read
The short answer
All three platforms are built for vertical 9:16 video at 1080 x 1920, so one master export can work everywhere. The differences are in length limits, music licensing and how each one handles content made in other apps.
Instagram recommends reels of 3 minutes or less to people who don't follow you. YouTube treats square or vertical uploads up to 3 minutes as Shorts. TikTok lets you record up to 10 minutes in the app and upload longer videos, per its support pages.
Spec comparison table
| Spec | Instagram Reels | TikTok | YouTube Shorts |
|---|---|---|---|
| Aspect ratio | 9:16 recommended | 9:16 vertical is native | Square or vertical (up to 9:16) |
| Recommended size | 1080 x 1920 (Meta's Reels ads guide lists 1440 x 2560) | 1080 x 1920 | 1080 x 1920 |
| Max length | Recommended to non-followers at 3 minutes or less; longer uploads possible in some cases | Up to 10 minutes recorded in app, up to 60 minutes uploaded | Up to 3 minutes to count as a Short |
| Music library | Instagram library; business accounts may see fewer tracks | Sound library; business accounts use the Commercial Music Library | Shorts audio library; claimed music over 1 minute can block a Short |
| Other-app watermarks | May reduce reach, per Instagram's creators FAQ | Avoid; post a clean original | Avoid; post a clean original |
| File format | MP4 or MOV, H.264, AAC | MP4 or MOV | MP4, H.264, AAC recommended |
Length limits, and where the sources disagree
Instagram is the messiest. Its creators FAQ says it recommends videos of 3 minutes or less to unconnected audiences. Meta's Reels ads guide lists durations up to 15 minutes, and Instagram's help pages have described recording longer reels too. In practice, keep anything you want discovered at 3 minutes or less, and check the limit your app shows.
YouTube is clear. Its help center says videos uploaded from October 15, 2024 with a square or vertical aspect ratio, up to three minutes long, are categorised as Shorts. A wider video, or one over three minutes, stays long-form.
TikTok's support page says videos recorded in the app can be up to 10 minutes, and uploads can be up to 60 minutes. If you choose a sound before recording, the sound's length sets the video length.
Length limits are not targets. Most reels that get watched to the end are far shorter than the maximum.
Aspect ratio and resolution
Export 9:16 at 1080 x 1920 and you are covered on all three. YouTube also accepts square Shorts, and Instagram supports other shapes, but vertical fills the screen and gives you the most room.
The bigger issue is the interface. Each app overlays buttons, captions and usernames on the bottom and right of the frame, and the layouts are not identical. Keep faces and text in the centre band so nothing is hidden on any platform. Meta's ads guide, for example, suggests keeping the top 14%, bottom 35% and 6% on each side clear of key text in Reels ads.
Music libraries: the biggest practical difference
Each platform licenses its own music library for use on that platform. A song you add inside TikTok is licensed for TikTok, not for your Instagram repost. That is why cross-posting with trending audio often ends in muted or blocked videos.
YouTube's help center adds a specific rule: a Short over one minute with an active copyright claim is blocked globally. Most songs from the Shorts audio library can be used for up to 90 seconds in a three-minute Short, though some are limited to 60 or 30 seconds.
Business accounts get fewer options. TikTok business accounts are steered to the Commercial Music Library, and Instagram business accounts can find that some popular songs are missing. Meta's Sound Collection offers royalty-free tracks for use in content on Meta's apps.
The safest cross-posting approach: export your video without music, or with a track whose licence clearly allows use on every platform, then add trending sounds natively inside each app.
Where each audience is
We won't quote audience statistics here, because public numbers vary by source and change fast. What you can say safely is how each app is built.
- Instagram Reels sits next to your photos, Stories and DMs. It suits people who already know you, local businesses and anything shared between friends.
- TikTok is a recommendation-first feed. New accounts can reach strangers quickly, and trends move fast.
- YouTube Shorts lives inside YouTube, so a Short can send viewers to your long videos and your channel.
Cross-posting without losing reach
Instagram's creators FAQ says watermarked reels and reposted content may reduce reach. Adam Mosseri has said publicly that your own logo is fine; the problem is logos from other apps. So never repost a TikTok download with the TikTok watermark on it.
- Keep a clean master file from your editor, before any app adds a watermark.
- Export one 9:16 master at 1080p or higher, then upload that file to each app.
- Add trending sounds inside each app, not in the master, unless the track is licensed for all of them.
- Rewrite on-screen text and captions per platform. Hashtags and hook wording often differ.
- Use an editor that does not stamp its own logo on free exports.
- Check each app's preview for buttons covering text before you post.
A simple workflow for posting one video to all three
Here is the routine we suggest. It takes a few extra minutes per video and avoids the common problems: muted audio, cropped text and reach lost to watermarks.
- Edit once in 9:16. Keep faces and captions in the centre of the frame, away from the bottom and right edges.
- Keep it under three minutes if you want it treated as a Short and recommended on Instagram. Under one minute is safest on YouTube if the audio might be claimed.
- Export a clean master at 1080 x 1920 or higher, as MP4. If you plan to use trending sounds, export a second copy with no music.
- Upload the master to Instagram and add the sound from Instagram's library if you want a trending track.
- Upload the same master to TikTok and pick the sound inside TikTok.
- Upload to YouTube as a Short, then check the audio has no claim before you share the link.
- Write a fresh caption and first line for each app instead of pasting the same text everywhere.
Which platform should you post to first?
If your audience already follows you on Instagram, post there first and treat the others as extra reach. If you are starting from zero and want strangers to find you, TikTok and Shorts both push new content to non-followers. If you also make long videos, Shorts is the obvious bridge.
Most people do best posting the same clean master to all three, with music and captions adjusted per app.
Sources
Frequently asked questions
Is it better to post on Reels, TikTok or YouTube Shorts?
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It depends on your audience. Reels suits people who already follow you on Instagram, TikTok is strong for reaching strangers, and Shorts helps if you also post long YouTube videos. Most creators post the same clean video to all three.
Can I post the same video on Reels, TikTok and Shorts?
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Yes, as long as you upload a clean file without another app's watermark and you use music licensed for each platform. Export one 9:16 master and upload it to each app.
How long can a YouTube Short be?
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YouTube's help center says square or vertical videos up to three minutes long, uploaded on or after October 15, 2024, are categorised as Shorts.
How long can a TikTok video be?
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TikTok's support page says videos recorded in the app can be up to 10 minutes and uploaded videos up to 60 minutes. Check the options your app shows, as limits can vary.
Does Instagram penalise TikTok watermarks?
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Instagram's creators FAQ says watermarked reels and reposted content may reduce reach. Your own logo is fine, but remove other apps' watermarks by posting your original export.