YouTube Shorts, TikTok and Instagram Reels look interchangeable at a glance — all vertical, all short, all built around the same swipe-to-next behaviour — but their technical limits differ enough that a clip built for one will genuinely look or perform worse on another if you upload it unchanged. Here is exactly how the three compare, spec by spec, and what that means for how you should actually export.

Aspect Ratio and Resolution

All three platforms are built primarily around 9:16 vertical video at 1080×1920, and this part is genuinely standardised across them — a 1080×1920 H.264 export will display correctly full-frame on every one of them. Where they diverge is in what happens when your source footage is not already 9:16.

YouTube Shorts accepts other ratios but crops or letterboxes anything that is not vertical, and Shorts eligibility itself depends partly on the aspect ratio — content wider than tall may simply be treated as a regular video rather than a Short, regardless of its length.
TikTok is the most forgiving of the three about non-vertical uploads, displaying 1:1 and 16:9 clips with blurred vertical padding rather than aggressive cropping, but engagement on non-vertical TikToks is consistently weaker because more of the screen is filled with padding rather than the subject.
Instagram Reels tightly enforces 9:16 in its own editor and crops other ratios to fit, generally centring the crop rather than letting you choose the frame after upload.

Maximum Duration

YouTube Shorts: up to 3 minutes as of the current Shorts specification (YouTube extended this from the original 60-second limit).
TikTok: up to 10 minutes for standard uploads, though the platform's own algorithm and audience behaviour still favour clips well under a minute for pure discovery reach.
Instagram Reels: up to 90 seconds.

The practical takeaway: if you are cutting one short-form clip to distribute across all three, cut to the tightest limit — Reels' 90 seconds — and that single export will fit within every platform's ceiling without modification. Only extend beyond that if you are deliberately building a longer-form Short or TikTok that will not be cross-posted to Reels unchanged.

Frame Rate and Bitrate

YouTube Shorts: 24-60fps supported; YouTube re-encodes on ingest regardless of source, targeting roughly 8-12 Mbps at 1080p depending on frame rate.
TikTok: 30fps standard, 60fps supported on newer app versions and devices; TikTok's own compression is historically the heaviest of the three, so starting from a higher-bitrate source export helps offset quality loss after upload.
Instagram Reels: 30fps standard; Instagram's compression is also aggressive, similar to TikTok's, which is why creators are consistently advised to upload the best 1080p file available rather than a pre-compressed one.

File Size and Codec

YouTube Shorts: follows YouTube's general upload limits (up to 256GB), which is far beyond what a short clip will ever need; H.264 or H.265 inside MP4 is standard.
TikTok: around 287MB uploading from the mobile app, up to roughly 500MB through the web uploader; MP4 or MOV, H.264 or H.265.
Instagram Reels: up to 4GB; MP4 with H.264 video and AAC audio.

Captions and Safe Zones

All three platforms overlay interface elements — captions, usernames, like/share buttons, sound attribution — along broadly similar zones near the bottom and right edges of a vertical frame, but the exact pixel margins differ slightly between apps and change periodically as each platform redesigns its UI. The safest practice, rather than memorising exact pixel numbers that will shift, is to keep essential text and faces within the centre 80% of the frame, leaving roughly a 10% margin on every edge clear of critical content.

Audio and Music Licensing Differences

This is one of the more consequential differences and has nothing to do with resolution. TikTok and Instagram Reels both operate large licensed commercial-music libraries built into their editors, so audio added through the in-app sound picker is generally cleared for use on that platform specifically. YouTube Shorts has its own separate licensed music library through YouTube's Shorts creation tools. Crucially, a track cleared for use on TikTok's in-app picker is not automatically cleared for reuse on YouTube or Instagram — the licence is tied to the platform and its own agreements with rights holders, not to the piece of content once it is exported as a file. If you are repurposing one short-form clip across all three platforms, either use each platform's own native music picker separately for each upload, or stick to your own original audio, royalty-free tracks you have a licence for, or fully silent/voice-only clips to avoid the licensing mismatch entirely.

Practical Export Settings for Cross-Posting

If your goal is one export that works cleanly everywhere, use:

Resolution: 1080×1920 (9:16)
Duration: under 90 seconds
Codec: H.264, MP4 container, AAC audio
Frame rate: match your source (usually 30fps)
Captions: burned in, kept within the centre 80% of the frame
Audio: original or licensed audio, added separately through each platform's native picker if you want algorithmic trending-sound benefits

This single export satisfies YouTube Shorts, TikTok and Instagram Reels without modification, and it is the export format assumed throughout our content repurposing guide, which covers the full workflow for cutting one longer recording into short-form clips for all three platforms plus podcast and written formats.

If You Need to Recover a Clip You Already Published

Lost the original export of a Short, TikTok or Reel you posted yourself? The TikTok downloader and Instagram downloader on this site can retrieve the publicly served file from your own post's URL, though bear in mind the retrieved copy reflects whatever compression the platform already applied — it will not restore quality beyond what was uploaded.

Algorithm Behaviour: A Non-Technical but Practical Difference

Specs aside, the three platforms distribute short-form content differently in ways that affect how you should cut a clip. TikTok's discovery feed leans heavily on completion rate within the first few seconds, which is why front-loaded hooks matter more there than almost any other factor. YouTube Shorts sits inside a broader ecosystem that also considers subscriber relationships and watch history from a viewer's regular YouTube activity, so a Short can perform well partly because of an existing channel audience rather than cold discovery alone. Instagram Reels weighs a mix of both — some cold discovery through the Explore-style Reels tab, and some distribution to existing followers — which is why the same clip can perform very differently across the three even when the technical export is identical.

Thumbnails and Cover Frames

YouTube Shorts lets you select or upload a custom cover frame that appears in the main YouTube app outside the Shorts feed itself (on your channel page, in search, in suggested videos), which is a genuine practical difference from TikTok and Reels, where the cover typically just reflects a frame from the video with minimal customisation. If your Shorts strategy includes driving traffic from your regular channel content, take the extra minute to set a deliberate cover frame rather than leaving it on the auto-selected default.

YouTube Shorts vs TikTok vs Reels: Video Specs Compared