What Changed in Facebook Ad Sizes for 2026?
Facebook's official ad specs for 2026 confirm a clear direction: mobile-first formats now dominate. The most versatile size remains 1080 x 1080 pixels (1:1), but for mobile Feed ads, the 4:5 aspect ratio (1080 x 1350) gives you more screen real estate. For Stories and Reels, 9:16 (1080 x 1920) is required to fill the full screen. With 81.8% of Facebook users accessing the platform only via mobile, ignoring these formats means leaving money on the table.
Why This Matters for Your Business
If you're still running 1:1 square ads everywhere, you're competing with one hand tied behind your back. On mobile Feed, a 4:5 ad occupies more vertical space, pushing organic content out of view and increasing the chance of engagement. On Stories and Reels, a 9:16 ad that respects safe zones (keeping key visuals centered) will outperform a poorly cropped square. Meta no longer enforces the 20% text rule, but ads with less text on images still get broader delivery. The bottom line: update your creative templates now to match these specs, or risk lower ad performance.
Which Formats Should You Prioritize?
Feed Ads: Go 4:5 for Mobile
For image and video ads in the mobile Feed, use 1440 x 1800 pixels (4:5). This gives you 25% more vertical space than 1:1. If your ad runs across multiple placements, stick with 1:1 (1440 x 1440) for predictable cropping.
Stories and Reels: 9:16 Is Non-Negotiable
Use 1080 x 1920 pixels for both. Keep your call-to-action and key visuals within the center 1080 x 1420 area to avoid UI overlays. Video Stories play 10 seconds at a time; longer videos get broken into multiple cards.
Carousel and Collection: Stick with 1:1
Carousel ads work best at 1080 x 1080 (1:1). Collection ads automatically crop to 1:1, so upload square images. For Advantage+ catalog carousel, 4:5 is supported.
What This Means for Your Business
If you run Facebook ads, you need to update your creative assets. The shift to mobile-first formats means that square ads on mobile Feed are now suboptimal. Businesses that adopt 4:5 for Feed and 9:16 for Stories/Reels will see better engagement and lower cost per result. If you only have resources for one format, default to 1080 x 1080 (1:1) — it still works across most placements. But for best performance, create placement-specific assets. The removal of the 20% text rule gives you more freedom, but keep text light for best delivery.
Your Move:
Audit your current ad creative this week. Replace any 1:1 Feed ads with 4:5 versions, and ensure all Stories and Reels use 9:16 with centered key visuals. Test one campaign with the new specs and compare results to your old creative.
FAQ
The best all-purpose size is 1080 x 1080 pixels (1:1). For mobile Feed, use 4:5 (1080 x 1350). For Stories and Reels, use 9:16 (1080 x 1920).
Yes, for mobile Feed ads. 4:5 takes up more vertical space, increasing visibility and engagement. For multi-placement campaigns, 1:1 is safer.
Image ads: 30MB. Video ads: 4GB. These limits apply across all placements.
No, Meta no longer enforces it. However, ads with less text on images still tend to get broader delivery and better results.
