A mockup that looks perfect in the editor can land on the timeline with the phone's top third amputated. Every network crops to its own ratio, and the crop happens after you post. The fix is boring and reliable: export at the platform's own ratio, and keep the device inside a safe area. The numbers below come from each platform's documentation, read on 9 September 2026.
The cheat sheet
| Platform | Placement | Export size | Aspect ratio | What the docs say |
|---|---|---|---|---|
| Link previews (Open Graph) | Any shared URL | 1200 × 630 | 1.91:1 | Recommended; 600 × 315 minimum for a large card, 8 MB cap |
| Feed portrait | 1080 × 1350 | 4:5 | Upload at 1080 px wide; ratio must sit between 1.91:1 and 4:5 | |
| Feed landscape | 1080 × 566 | 1.91:1 | The widest ratio the feed keeps without cropping | |
| X | Post image | 1200 × 1200 | 1:1 | X recommends 16:9 or 1:1 for post imagery |
| X | Link card | 1200 × 628 | 1.91:1 | The size X publishes for 1.91:1 creative |
| YouTube | Video thumbnail | 3840 × 2160 | 16:9 | Recommended resolution; 640 px minimum width, JPG or PNG |
| Product Hunt | Gallery image | 1270 × 760 | ~5:3 | Recommended gallery size; the gallery needs 2 images to appear |
| Dribbble | Shot | Upload large, crop in place | Set by the cropper | No fixed export size — 10 MB upload limit and an in-app cropper |
Sources: Meta — Open Graph image specs · Instagram Help — image resolution · X Business — creative best practices · YouTube Help — custom thumbnails · Product Hunt Help — how to post a product · Dribbble — more pixels and a perfect crop
Stories and Reels are the one placement with no published pixel size: they are simply full-screen, so 9:16 is the ratio and 1080 × 1920 is what everyone exports. Treat that figure as convention rather than specification — unlike every row in the table above, it is not a number Instagram documents.
If you only export one landscape master, make it 1200 × 630 — the Open Graph size. It renders acceptably on X, LinkedIn, Slack, Discord and iMessage link previews, which is where most B2B mockups are actually seen.
Safe areas: why devices get decapitated
Feed algorithms crop from the edges inward, and preview thumbnails crop harder than expanded views. Keep the device inside the central 80% of the canvas — roughly a 10% margin on every side. For 9:16 Stories, keep the top and bottom bands clear: that is where usernames, captions and reply bars sit on top of your image.
Portrait beats landscape on mobile feeds
Instagram's 4:5 portrait is the tallest ratio the feed keeps intact, so it occupies more screen height than a landscape image in the same scroll — and a phone mockup is itself portrait, so the formats agree. On X and LinkedIn, landscape stays the default, and a tilted or angled phone fills the frame better than an upright one. Match device orientation to canvas: upright phone for portrait posts, angled phone or laptop for landscape.
One design, five exports
- 01Compose the mockup scene with the device centred and generous background margins.
- 02Export the Open Graph master at 1200 × 630 for link previews and your blog post.
- 03Re-crop to 1080 × 1350 for the Instagram feed — the margins you left absorb the ratio change.
- 04Re-crop to 1200 × 1200 for X, which recommends 1:1 or 16:9.
- 05Export a 9:16 vertical for Stories, moving the device into the centre band away from the UI overlays.
MochiMockup renders at 2K on the free tier, which covers every size in the table except a full-resolution YouTube thumbnail — 3840 × 2160 is the one placement that wants a 4K Pro export.