Before and After Video Sizes for Reels, TikTok and Shorts

You have built the pair. The comparison mode is right, the reveal plays the way you wanted, and you are looking at the export sheet trying to work out whether 9:16 is actually what Instagram wants, whether TikTok wants something different, and whether the divider you spent ten minutes getting right is going to end up sitting under your own caption. This is the part nobody explains before you get there, and it is shorter than it looks.

One canvas covers almost everything

Reels, TikTok and YouTube Shorts all want the same shape: 9:16, exported at 1080 by 1920 pixels. Not three different specs to juggle, one. If you are making this for any combination of those three platforms, there is nothing to decide between them at export time. Pick 9:16 once and the file works everywhere you were going to post it.

That single fact is worth sitting with, because most of the anxiety about video sizes comes from assuming each platform is fussier than it actually is. They are not fussy about the canvas. They are fussy about what sits inside it, which is the part that actually needs planning.

The safe area, and why it exists

Every one of those three apps lays its own interface on top of your video once it is posted. A caption and a sound line near the bottom. A column of icons down the right edge: like, comment, share, bookmark, sometimes a profile thumbnail above them. None of that is part of your export. All of it is added by the platform after the fact, and it sits in roughly the same place on Reels, TikTok and Shorts because all three are solving the same problem: get out of the way of the video while still fitting the controls somewhere.

The practical result is a safe area, a region in the middle of the 1080 by 1920 frame, roughly 900 by 1400 pixels, centred, that survives the interface on every one of the three. Anything inside it stays visible. Anything outside it, especially in the bottom strip and down the right edge, is a gamble on whichever platform you post to that week.

This matters for a before and after pair specifically because the whole content is the comparison itself. A caption graphic that gets covered is a nuisance. A divider, a label or the actual seam between your before and after getting covered is the entire post failing at its one job.

Where a divider must not sit

If you are exporting with Slider as your comparison mode, the divider is not decoration, it is the reveal. A viewer’s eye is meant to follow it. Put the moving line, or the part of the frame doing the most work, in the bottom strip where a caption sits, or in the right-hand strip where the action icons sit, and you have built a video whose one job is to be watched and then covered it with a button.

The fix is not complicated: keep the subject and the divider inside the centred safe area described above, and treat the outer edges, especially the bottom fifth and the right-hand column, as space you cannot rely on. Most of the templates on this site are already built with that margin in mind, but it is worth checking your own crop before you export, particularly if your subject is close to one edge of the frame already.

One honest limit sits underneath this. The video exporter currently takes its layout from the reveal animation you chose rather than from the comparison mode, so a pair built in Top / Bottom or Tap to Switch reaches a correct still image export today, but the video export follows Slider Reveal’s own layout regardless of which mode you picked. If your export is a video and you built one of those two modes, check the result against the safe area rather than assuming it matches the layout you designed in the editor.

4:5 for a feed post, 1:1 for a grid

Outside the three video platforms, two more ratios cover most of what is left. 1:1, a plain square, is the one to reach for when the destination is a grid, because a square crops the same in a small profile thumbnail as it does full size in the feed, and nothing about the shape changes between those two views.

4:5 is the taller option, and it is worth using when a single post is the whole point rather than the grid it sits in. It is the tallest ratio most feeds display before they start treating the post like a Reel, so it uses more of the screen than a square without turning into a different content type.

Here is the part worth saying plainly rather than discovering at the export sheet: 9:16 and 1:1 are free. 4:5 and Original are Pro. If your whole plan is Reels, TikTok, Shorts and a square grid post, the free ratios already cover every one of those destinations. The Pro ratios exist for the two cases that fall outside that list: a taller single feed post, and anything that is not vertical at all.

Original, for the case 9:16 was never going to fit

A driveway, a whole room, a garden bed: wide subjects lose almost everything once they are forced into a 9:16 frame, because the width is exactly what a vertical crop throws away first. Original keeps your source proportions instead of forcing a ratio on it, and it caps the longest side at 3024 pixels, which is more than enough for a website hero image or a standard YouTube upload.

This is also the export to reach for if the destination is a website page or a normal YouTube video rather than a Short, since neither of those wants a vertical frame at all. Decide the destination before you shoot if the subject is wide, because a wide pair cropped down to 9:16 after the fact loses the argument the video was supposed to make.

Decide the ratio before you export, not after

The mistake that actually costs people time is not picking the wrong ratio, it is picking the right one after the divider, the label and the crop were already set for a different one. A re-crop on export is what pushes a caption over a divider that used to be clear of it. If you already know the video is going to Reels and TikTok, build it at 9:16 from the start. If it is a website hero, build it wide. Deciding late is what makes the safe area feel like it is fighting you, when it is actually just waiting for you to build inside it in the first place.

Checking the pair before any of this matters

None of the ratio decisions above matter if the underlying pair does not hold together in the first place. The free before and after slider on this site runs entirely in your browser: drop your two photographs in, drag the handle, and nothing leaves your device. It is a fast way to confirm the comparison itself works before you spend time deciding which of five ratios to export it at.

If you are still working out the whole flow from photograph to finished export, how to make a before and after video from two photos walks through every step in order, including the ratio decision covered here in more depth against the other export choices around it.

Picking a template that already respects the safe area

You do not need to design the safe area yourself. Reels Ready is built specifically around the vertical platforms, with the caption and label positions already clear of the bottom strip and the right-hand column. The TikTok template does the same for TikTok’s own caption placement, which sits slightly differently from Instagram’s. Both sit in the social category, alongside templates built for Stories, YouTube Shorts and a feed grid, if neither is quite the register you want.

Once you know the app itself, the app page has the full breakdown of comparison modes, reveal animations and the free-versus-Pro export split, including everything referenced here.

The short version

One canvas, 9:16 at 1080 by 1920, covers Reels, TikTok and Shorts without a re-crop between them. Keep the divider, the subject and the label inside a centred safe area, roughly 900 by 1400, because the bottom strip and the right-hand column belong to the platform, not to you. 1:1 for a grid, 4:5 for a single feed post that wants more screen, both free on 9:16 and 1:1, both Pro on 4:5. Original when the subject is wide enough that a vertical frame was never going to hold it. Decide which one you need before you build the pair, and the export sheet stops being a decision and starts being a formality.