Instagram Reels ads are 1080x1920 at 9:16, MP4 or MOV, H.264 with AAC audio, and 1080p is all you need because Instagram re-encodes anyway. The spec that actually decides whether the ad works is what Instagram draws on top of that frame: plan for roughly the top 14 percent and bottom 20 percent being covered, plus a strip down the right side for the action buttons, which leaves a usable middle of about 1080 by 1270 pixels. Everything a viewer has to read, including the offer, belongs in that middle.
What the frame looks like once Instagram has drawn on it
The published spec gives you a canvas. The interface then takes pieces of it back. On a 1080x1920 export the bands work out roughly like this.
| Band | Roughly | What Instagram draws there | What you can put there |
|---|---|---|---|
| Top strip | 0 to 270 px, top 14% | Status bar, back control, the ad label on some surfaces | Sky, texture, nothing you need read |
| Upper middle | 270 to 700 px | Nothing | Headline text, price, product name |
| Lower middle | 700 to 1250 px | Nothing | Subject's face, product in use, captions |
| Right rail | rightmost ~140 px, from about 55% to 90% of height | Like, comment, share, audio and more controls | Background only, keep the subject clear of it |
| Bottom block | 1536 to 1920 px, bottom 20% | Profile row, primary text, sound attribution, CTA button | Nothing at all |
Those are working margins, not published constants: Meta changes interface heights, the CTA sits lower on Instagram Reels than on Facebook Reels, and a long primary text or an expanded comment overlay eats more of the bottom than the margin allows. They also compound, because the right rail overlaps the lower middle, so a tightly cropped talking head can have the share button on their shoulder while the composition looks fine in your editor. Our safe zone reference covers how this plays out across the other placements.
Where does the offer go?
The useful consequence of the map above is that vertical position is a decision, not an accident. We treat the frame as three jobs.
The upper middle, roughly 15 to 35 percent of frame height, is where a burnt-in claim or price survives everything. It is above the caption block, below the top strip, and clear of the right rail. If the ad has one line of text that must be read, it goes here.
The lower middle, 35 to 65 percent, is for the thing being demonstrated. Faces, hands, the product doing what it does. This is also where captions sit, which is why the claim goes above rather than below: two text elements in the same band fight each other.
The bottom 20 percent gets nothing. Not a smaller logo, not a discount code, not the end-card CTA. If your end card currently has "Shop now, 20 percent off" across the lower third, it is being read by nobody, because Instagram has drawn its own CTA button over most of it.
The mistake we see most often is an end card centred in the full 1920: the first line lands at 960 and looks fine, the second drops to 1600 and disappears. Compose end cards inside 270 to 1250 like everything else.
How long should a Reels ad be?
Eight to 20 seconds covers almost everything that performs, and 10 to 15 is where we start. Reels will accept considerably longer, and that ceiling is not a target. Median hook rate on Meta Reels sits around 28 percent, so about seven in ten impressions never reach three seconds, and median video CTR is about 1.78 percent, which is actually the strongest of the placements we track. The audience is there, it just arrives and leaves quickly.
Length also has to be paid for. Our 2026 fatigue benchmark, a synthesis of published platform and agency figures, puts CTR decline at 15 to 20 percent over a creative's first two weeks, with week three landing 45 to 70 percent below the launch baseline, and most creative effectively dead inside three weeks. A 40 second Reel expires on the same schedule as a 12 second one and costs several times more to make. That is the argument for short: replacement economics, not attention spans.
Two structural notes specific to Reels. The loop counts: a Reel that cuts hard back to frame one reads as a second view and buys a little more watch time, so avoid finishing on a fade to black. And the offer has to land well before the midpoint, because the audience at second 15 of a 20 second ad is a fraction of the audience at second three.
Captions are a requirement, not an option
Reels autoplay muted for a large share of impressions, and you do not get to know which ones. So the caption track is the script, not an accessibility extra.
Instagram will generate captions automatically, and we would not rely on them. They use Instagram's styling, sit where the app puts them, mishandle product names, and can be switched off by the viewer. Burn your own in inside the margins and you control all four. Our approach to captions and text overlays fixes them at a set height in the lower middle band and sizes them per exported ratio rather than scaling one style across every placement.
Three caption rules that survive contact with real campaigns:
- Two lines maximum, and a line length that fits inside 1080 minus the right rail at your chosen type size.
- Hold each caption long enough to be read, not long enough to match the audio. Reading is slower than listening.
- Never let a caption run under 1500 pixels, even for one frame, because that is where the profile row starts.
How Reels creative differs from feed creative
Same footage, different build. The spec differences are the obvious part and the composition differences are what actually costs money.
| Instagram Reels | Instagram feed | |
|---|---|---|
| Ratio and size | 9:16, 1080x1920 | 4:5, 1080x1350 |
| Interface over the video | Top, bottom and right side | Below the video, not over it |
| Burnt-in headline | Needed, nothing else carries the message | Usually a mistake, Meta draws its own headline below |
| Length we ship | 8 to 20 seconds | 10 to 25 seconds |
| Median CTR | About 1.78 percent | About 1.62 percent |
| Sound | Muted by default, audio attribution shown | Muted by default |
The line that matters is the third. In feed, Meta renders the headline, description and CTA in its own block under the video, so burning a headline into a 4:5 asset stacks two headlines. In Reels there is no such block, so a message that is not on the frame is not communicated. Reels and feed want opposite text treatments, which is why cropping one into the other is wrong in both directions.
Producing the Reels cut without a separate edit
Disclosure: Genyad is our product. It works from footage you already own, transcribes and tags every clip, then builds each variation as its own script, shot selection, voiceover, caption set and export, so the 9:16 version is composed for 9:16 rather than cropped from a wider master. Captions land inside the Reels margins, and the same variation also exports 4:5, 1:1 and 16:9 with text repositioned per ratio. The Instagram Reels ad maker page walks through it, and the free plan covers five variations without a card.
What it does not do: no AI avatars or synthetic presenters, no static banner formats, no product-URL import, no predicted performance scores, and no publishing to Instagram. You export the file and upload it in Ads Manager yourself.
Frequently asked questions
What size should an Instagram Reels ad be?
1080x1920 pixels, 9:16, as MP4 or MOV with H.264 video and AAC audio. 1080p is sufficient because Instagram re-encodes on upload, so a 4K master mainly costs you upload time. Send the native 9:16 file rather than a padded one, since black bars count as part of your creative.
How much of an Instagram Reels ad is covered by the interface?
Plan for the top 14 percent and the bottom 20 percent, which is about 270 pixels and 384 pixels on a 1080x1920 export, plus a strip roughly 140 pixels wide down the right side for the action buttons. Those are working margins rather than fixed values, because Meta changes interface heights and Facebook Reels places the CTA differently. Composition should sit inside them with room to spare.
How long should an Instagram Reels ad be?
Eight to 20 seconds, and we start at 10 to 15. The platform accepts much longer, but median hook rate on Meta Reels is around 28 percent, so most impressions never reach three seconds and extra runtime is spent on a shrinking audience. Longer edits also cost more to replace, and most creative is effectively dead within three weeks.
Do Instagram Reels ads need captions?
Yes, treat them as part of the deliverable. Reels autoplay muted for a large share of impressions, so the captions carry the script rather than supplementing it. Burn your own in rather than relying on Instagram's automatic captions, which use Instagram's styling, sit where the app puts them, mishandle product names and can be turned off by the viewer.