One clip, three platforms: TikTok, Reels and Shorts specs

One export, three platforms

The encoding requirements of TikTok, Instagram Reels and YouTube Shorts have converged to the point where a single file serves all three. That file is:

Export that once and upload it everywhere. Producing three variants is a habit left over from when the platforms genuinely differed, and it triples the most tedious part of the work for no benefit.

What still differs between the platforms is not the encode. It is runtime limits, what counts as a Short, and — the one that actually bites — where each platform puts its own interface on top of your video.

YouTube treats a vertical video as a Short based on its aspect ratio and duration, rather than requiring a separate upload path.

YouTube Help — Create a Short

The safe area is the real difference

Every vertical platform overlays interface on the video: the caption text and account handle along the bottom, action buttons down the right-hand side. Your video plays underneath all of it.

This is why captions placed near the bottom of the frame get covered on at least one platform, and why you will not notice in your editor, where the frame is clean.

The reliable zone is the middle third, kept clear of the right-hand edge. Text there is legible everywhere, it survives the platform redesigns that happen without notice, and it is where the eye already is if the speaker is centred.

If you would rather see it than take it on trust, the safe zone checker draws all three interfaces over a frame of your own. It runs in your browser, nothing is uploaded, and it is the fastest way to find out that the line you were most proud of sits under a username.

Treat this as a hard constraint rather than a guideline, because the failure is invisible to you and total for the viewer: a hook line covered by a username is a hook that did not happen. It is the same argument as placing captions in the middle third, and it applies to any burned-in text — titles, labels, calls to action.

Runtime

All three accept clips well beyond the length short-form actually rewards, so the limits are rarely the binding constraint.

YouTube Shorts is defined by aspect ratio and a duration ceiling; go past it and the upload is treated as a regular video rather than rejected. TikTok and Reels both accept lengths far longer than a typical clip.

The practical point is that platform limits should not be driving your decisions. The structure of the clip should. Twenty to sixty seconds covers most conversational clips because that is what a hook, a payoff and an ending require — not because a platform said so.

Where the ceilings matter is the edge case: a long story that runs past the Shorts threshold either gets split or gets published as a regular vertical video, and those are different products with different audiences.

What should change per platform

Three things, and none of them is the file.

The caption text — the description you type when uploading. Each platform has different conventions, different character limits and a different audience temperature. This is also where hashtags go, and hashtag practice differs enough between them to be worth the thirty seconds.

The cover frame. Each platform shows your clip as a still in a grid. Choose a frame with a face mid-expression rather than whatever the first frame happens to be. On the platforms that let you set it explicitly, do.

The posting time. Audiences differ per platform, and so does when they are on it.

That is the whole list. Re-encoding, re-cropping, re-captioning per platform is work that produces no measurable difference and eats the hour that was supposed to go into the next clip.

The cover frame is a per-platform decision

Every platform shows your clip twice: playing in the feed, and as a still in a grid — your profile, a search result, a suggested-videos rail. The still is chosen for you unless you choose it, and the default is usually whatever the first frame happens to be.

First frames are reliably bad covers. Speakers blink, mouths are half open, the camera has not settled. A frame taken a second or two in, with a face mid-expression, does better, and on the platforms that let you upload a separate cover image you can do better still.

This is worth thirty seconds per clip because the grid still is what a new viewer sees when they land on your profile after one good clip. A wall of blurred half-blinks reads as an abandoned account regardless of what the videos contain.

Set it per platform, since each one crops the grid thumbnail differently — square on some, vertical on others. The same frame can be fine in one and beheaded in another.

The watermark rule

Do not download your own post back from one platform and upload it to another.

Every platform adds a visible watermark to downloads, and every platform is understood to suppress content carrying a competitor's mark. Whether the suppression is as strong as folklore suggests is unclear; that it is trivially avoidable is not.

Export from your editor, upload the clean file to each platform separately. The only reason people do otherwise is that the download is convenient, and the convenience is not worth finding out.

Resolution, upstream

The specification says 1080 x 1920, and hitting it depends on a decision made before you record.

Cropping a 1080p widescreen recording to 9:16 leaves roughly 608 pixels of width. That is well below 1080, so the player upscales, and the clip is visibly softer than the ones around it — no error, no artefact, just consistently less crisp.

Recording in 4K leaves about 1216 pixels after the same crop, comfortably above target. This is the strongest reason to record at higher resolution than you publish: not detail, crop budget.

If you are working from 1080p sources you cannot re-record, crop less aggressively where framing allows and accept the softness. It is a real cost but a small one next to a clip that never gets cut at all.