About Social Media Image Sizes
Two numbers decide whether your image survives being posted, and most size guides only give you one. The upload dimensions tell you what to export. The aspect ratio tells you what the platform will crop to — and it will crop, silently, if your ratio does not match. An image at the right pixel dimensions but the wrong ratio still gets cut.
Safe zones are the other half of the problem. Several platforms draw their own interface on top of your image: YouTube's channel banner is 2560×1440, but only a 1546×423 region in the centre is visible on every device, which is why so many channel banners have text hanging off the edge on a phone. Those regions are marked here rather than left for you to discover after publishing.
One general rule worth knowing: export at the size listed or larger, never smaller. Every platform re-encodes what you upload, and upscaling a small image before compression produces visible mush. Starting larger and letting the platform downscale gives a noticeably cleaner result.
How to use the size guide
Pick your platform
Each tab lists every image slot that platform uses, with the file size and format limits.
Check the aspect ratio, not just the pixels
The ratio is what gets enforced. Matching it matters more than hitting the exact pixel dimensions.
Respect the safe zone
Where one is shown, keep text and faces inside it. Everything outside is cropped on some devices.
Exporting images that survive compression
- Export at the listed size or a clean multiple of it. Never upscale a smaller image to fit.
- Use PNG for graphics with flat colour and text; JPG for photographs. PNG text stays crisp where JPG smears it.
- Keep files under the platform's limit — YouTube thumbnails are capped at 2 MB, and an over-size upload is simply rejected.
- Test thumbnails at the size people see them. A YouTube thumbnail is often displayed around 360×202, where fine detail disappears entirely.
- Avoid text near any edge. Different devices crop differently, and the edges are what they take.