820×312 on desktop, less on mobile
Facebook's page cover photo displays at 820 × 312 pixels on desktop. On a phone, the same cover photo is cropped down to roughly 640 × 312 — the height stays the same but a strip is trimmed from each side. Since most visitors to most pages are on mobile, that narrower crop is often what the majority of your audience actually sees, even though 820x312 is the size you upload.
The shaded safe zone in the preview
The preview overlay marks that central 640×312 area directly on your photo — roughly 90 pixels on each side fall outside it. Anything in that outer strip is part of the full desktop cover but disappears on mobile. That's not automatically a problem — a background texture or an out-of-focus edge is fine to lose — but a logo, a face or text positioned there will read as present on desktop and missing on mobile, which usually isn't the intended effect.
| Where | Size shown |
|---|---|
| Desktop | 820 × 312 (full cover) |
| Mobile | ~640 × 312 (centre crop) |
Why crop around a focal point
820x312 is a wide, short strip — roughly 2.6:1 — and very few source photos start out that shape. A straight centred crop only works if the subject already sits in the middle of the original image; anything positioned to one side gets cut away once the photo is cropped down to a banner this shallow. Dragging the focal point onto whatever has to stay visible — a face, a product, the readable part of a background — builds the crop around that point instead, and keeps it inside the mobile safe zone if you check the overlay while positioning it.
Does the profile picture cover part of it too?
On some layouts the profile picture sits slightly over the bottom-left of the cover photo, similar to how header images work on other platforms, but it's a minor overlap compared to the desktop/mobile size difference above, which is the change that actually affects what most visitors see. The safe-zone overlay here is built around that bigger, more consistent difference.
Upload larger than 820×312 if you have it
Facebook re-compresses cover photos regardless of the source resolution, so a higher-resolution original doesn't make the final cover objectively sharper once it's live — but it does give the crop more detail to work with before quality starts to soften, particularly if the focal point ends up cropping in tightly. This tool downscales from whatever you provide down to 820x312; it's upscaling a source that's already too small that causes visible softness, not starting large.
Output is JPEG at high quality. Everything runs in your browser using the canvas API — the photo is never uploaded to a server, there's no account or sign-up, and no file size limit beyond what your own device can handle.