Cover size guide: ratios, canvases, and platform targets
Pick the wrong aspect ratio and even a good image loses its subject to a crop. This guide lists recommended dimensions and ratios for common publishing surfaces, and explains how Muse Image's three output canvases map onto them. Platform specs change; the platform figures below were checked on 31 July 2026, so confirm against the official docs before you ship.
Choose the ratio first, worry about pixels later
At generation time the aspect ratio is what matters, because it drives composition — where the subject sits, how much margin there is, whether it still reads as a thumbnail. Pixel dimensions belong to delivery: any high-resolution image at the right ratio can be cropped to the target size. So pick the ratio in Muse Image, then crop on export.
What Muse Image actually outputs
Muse Image returns PNG on one of three canvases: 1536×1024 landscape, 1024×1536 portrait, or 1024×1024 square. The ratio you select goes into the prompt and steers composition, then the system renders on the closest supported canvas. That is why 16:9 and 1.91:1 both render at 1536×1024, and 9:16 and 3:4 both render at 1024×1536 — the difference shows up in composition, and you crop to the exact ratio on delivery.
Why you should leave a crop-safe area
One image gets cropped differently in different places: a 16:9 cover may be squared off in a feed and reduced to its centre on mobile. Keeping the subject and its breathing room inside the centre safe area, with nothing important against an edge, is the cheapest way to make a single image work in several placements. Product Studio composes to this rule by default.
| Surface | Recommended size | Ratio | Choose in Muse Image | Rendered canvas |
|---|---|---|---|---|
| YouTube video thumbnail | 3840×2160 (640px minimum width; 1280×720 is the quality floor) | 16:9 | 16:9 | 1536×1024 |
| YouTube podcast playlist cover | 1280×1280 | 1:1 | 1:1 | 1024×1024 |
| Open Graph link preview (Facebook, LinkedIn, Slack, Discord) | 1200×630 | 1.91:1 | 1.91:1 | 1536×1024 |
| X large summary card | 1200×675 | 16:9 | 16:9 | 1536×1024 |
| Xiaohongshu vertical cover | 1080×1440 | 3:4 | 3:4 | 1024×1536 |
| Vertical video and story covers | 1080×1920 | 9:16 | 9:16 | 1024×1536 |
| Square feed image | 1080×1080 | 1:1 | 1:1 | 1024×1024 |
| Blog post hero | 1600×900 | 16:9 | 16:9 | 1536×1024 |
| Podcast show artwork | 3000×3000 | 1:1 | 1:1 | 1024×1024 |
| Ultra-wide banner | 2560×1080 | 21:9 | 21:9 | 1536×1024 |
What size should a YouTube thumbnail actually be?
YouTube's help documentation currently recommends 3840×2160 at 16:9, with a 640-pixel minimum width. The old 1280×720 figure is now a quality floor rather than a target — thumbnails below 720p get downscaled to 480p in thumbnail A/B tests. Generate at 16:9 and upscale or crop on export.
Is 1200×630 the official Open Graph image size?
No. The Open Graph protocol defines og:image and its width and height properties but specifies no dimensions. 1200×630 (1.91:1) is a de facto standard formed by platform recommendations — Facebook advises at least 1200×630 for a high-resolution preview. That is why different guides quote 1200×628 or 1200×627.
Why is the Muse Image canvas not exactly 16:9?
The image model supports three canvas sizes. 1536×1024 is actually 3:2, the closest landscape option. Your chosen ratio still enters the prompt and drives composition, so cropping to the exact target ratio on export gives you the precise size without cutting into the subject.
Can one image serve several platforms?
Yes, if it was composed with a crop-safe area. Keep the subject centred and nothing critical against an edge, and one 16:9 image can yield a 1.91:1 link preview and a 1:1 feed crop. For vertical placements, generate 9:16 or 3:4 separately — cropping a landscape image to vertical usually loses too much of the frame.