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.