Reels Ad Specs: Size, Safe Zones, and What Matters
Reels ad specs in plain terms: 9:16 vertical at 1080x1920, UI-aware safe zones, sound-off captions, and a hook up front. Everything else is testing.
Instagram Reels ads are full-screen vertical video: 9:16 aspect ratio, typically 1080x1920, with key content kept inside the safe zone so Instagram's overlays (caption text, account name, CTA button, and the icon stack on the right) don't cover it. Exact duration limits and file requirements change periodically, so verify them in Meta's ads manager at upload time. The durable specs are vertical framing, safe-zone discipline, and an opening that earns the next second.
What resolution and ratio do Reels ads use?
Shoot or render at 9:16, 1080x1920 minimum. Reels will display other ratios, but non-vertical creative gets cropped or pillarboxed and immediately signals "repurposed ad." If you're adapting an existing horizontal asset, rebuild it vertically rather than center-cropping. The framing decisions that work at 16:9 rarely survive the crop.
Where do Instagram's overlays sit?
Reels stacks UI along the bottom (caption, audio attribution, CTA) and down the right edge (like, comment, share). As a working rule, keep anything essential out of the bottom fifth of the frame and off the right rail. Burned-in captions should sit in the middle band of the screen, not at the bottom where platform text competes with them.
How important is the hook on Reels?
Decisive. Reels is a swipe feed, and the viewer's decision to stay happens in the opening moments. Lead with the strongest visual or claim. Don't spend the first seconds on a logo card or slow establishing shot. Track hook rate per variation to learn which openings hold attention, and use a hook generator when you need fresh angles to test.
Should Reels ads be built for sound-off?
Assume a meaningful share of viewers watch muted. The ad should make sense with the sound off (clear visuals, on-screen text carrying the argument) while still rewarding sound-on viewers with voiceover and music. Burned-in captions are the simplest way to satisfy both.
What matters after the specs are right?
The specs are a checklist; the results come from creative iteration. Which hook, which angle, and which style of ad converts for your product depends on your margin, your audience, and the auction. Nobody can tell you in advance, and ROAS only reveals itself after you test. So the real spec is volume. Polaris turns that into a chat: connect it to Claude via MCP, attach a product photo, and generate spec-correct 9:16 UGC ads directly inside Claude in parallel batches with one-click captions. It's the fastest path to a testing pipeline of AI UGC ads, and the first batch of 12 is free. Once results land, sanity-check the economics with a ROAS calculator.