Shorts vs Reels vs TikTok: the clip specs that actually differ, and the safe zone nobody checks

The good news about clipping for three platforms is that the file is the same file: 1080x1920, 9:16, MP4, H.264, under a minute. The bad news is that "same file" hides three things that do differ — length limits, the UI each app paints over your video, and what each algorithm counts as a short — and a clip cut for one can quietly underperform on the others.

Specs move; these are from the platforms' own guidance as of September 2026, and the safe-zone numbers are approximate on purpose, because every app update shifts them by a few pixels.

The specs

	YouTube Shorts	Instagram Reels	TikTok
Aspect ratio	9:16	9:16 (4:5 tolerated)	9:16
Resolution	1080x1920	1080x1920	1080x1920
Max length as a "short"	3 min (was 60s until late 2024)	3 min	10 min standard
Sweet spot for a clip	20–60s	20–60s	20–60s
Captions	your burned-in ones, or auto	your burned-in ones, or auto	your burned-in ones, or auto
Audio	any; music library optional	licensed library or original	licensed library or original
Cover / thumbnail	pick a frame	pick a frame or upload	pick a frame + text

Two things to notice.

The length caps are no longer 60 seconds, and it doesn't matter. Shorts and Reels both allow three minutes now; TikTok allows far more. But the shelf your clip gets placed on, and the audience's expectation of a clip, still sits under a minute. A 90-second excerpt is a video, and gets judged on retention like one. Why we cap clips at 60s.

Everything else is identical. Which is why the platform differences that matter aren't in the file at all. They're painted on top of it.

The safe zone: what each app covers

Every app overlays UI on your video: the caption, the account name, the like/comment/share rail, the sound attribution, the progress bar. Anything you burn in underneath that overlay is unreadable, and the overlays are in different places on each app.

Approximately, as a fraction of the 1920px height and 1080px width:

Region	YouTube Shorts	Instagram Reels	TikTok
Top covered	~10% (search, camera)	~8%	~7% (For You / Following tabs)
Bottom covered	~20% (title, channel, sound)	~25% (caption, sound)	~30% (caption, sound, progress)
Right rail covered	~15% (like/comment/share)	~15%	~15%

So the region you can rely on being visible on all three is roughly the middle 55–60% of the height, and the left 85% of the width. Burned-in captions want to sit in the vertical centre or just below it — not along the bottom where a TV subtitle would go, which is the single most common mistake and exactly where TikTok's own caption and sound line sit.

We place captions in the lower-middle band for this reason, and keep them off the right edge. If your tool puts captions at the bottom, they're being covered on TikTok for everyone who didn't tap to hide the UI, which is nobody.

Two related traps:

• Text in the source video. Lower-thirds, name straps, on-screen titles from the original edit. The 9:16 crop keeps 56% of the width, so a lower-third that fitted the widescreen frame is now half cut off and sitting under the UI. The tool can't fix this; it's why the vertical crop is best done from a clean master where possible.
• Faces near the edge. A crop that's technically on the speaker but has their face in the right 15% puts it under the like button. This is a framing problem, and good reframing keeps faces in the centre band for this reason as much as for composition.

What each algorithm cares about

The mechanics are similar (completion rate, rewatches, shares, and whether the first two seconds held) but the audiences aren't, and the same clip reads differently.

Shorts gets its viewers from the same channel that posts the long-form. A Short that works as a trailer for the full video — a question the video answers — does double duty; the "watch full video" link is a real lever. Titles matter more here than elsewhere because Shorts show the title text.

Reels are the most caption-dependent. A high share of Reels are watched muted, and the platform's own caption UI is small. If your burned-in captions are the only way the clip makes sense without sound, Reels is where that pays off most.

TikTok rewards the raw moment and punishes anything that reads as repurposed. The same clip that does well on Shorts with a clean title card often does better on TikTok without it. Reaction and comedy content in particular travels here.

One clip, three uploads: what to actually change

You don't need three edits. You need one clip made correctly and three uploads with different metadata.

1. The file: 1080x1920, captions in the centre band, faces in the left 85%, nothing important in the bottom 30%. Make it once.
2. Shorts: add a title that's a question or a claim; link the full video; consider a title card if the clip is from a series.
3. Reels: write the caption text out in the post caption too (it's searchable there); pick a cover frame where the face is clear.
4. TikTok: shortest possible on-screen text, original sound, and post it as a moment, not an excerpt — no "from episode 42" framing.

If the clip needs different cuts per platform, the clip is probably wrong for one of them, and it's usually length: the bit that suits TikTok at 25 seconds is the same bit that suits Shorts at 25 seconds. The metadata is what differs; the moment doesn't.