YouTube Video thumbnail requirements
The published requirements are already set. Add your image and FileBelow makes it match — 16:9 · at least 640px wide · under 2 MB · JPEG or PNG.
JPG, PNG, WebP and HEIC. Your file is processed on your device.
YouTube recommends 3840×2160 and requires a minimum width of 640 pixels at a 16:9 ratio. The documented size limit is 2 MB when uploading from the mobile app and 50 MB from desktop, so FileBelow targets 2 MB — a thumbnail under 2 MB is accepted by both.
Official source · checked 2026-08-21
The published requirements
| Minimum width | 640 px |
|---|---|
| Aspect ratio | 16:9 |
| Maximum file size | 2 MB |
| Accepted formats | JPEG, PNG |
Read from support.google.com on .
Platforms change their requirements without notice. If this page disagrees with the source, the source is right — please tell us so we can correct it. Changes are recorded in the changelog.
What these numbers mean in practice
YouTube recommends 3840×2160 and requires a minimum width of 640 pixels at a 16:9 ratio. The documented size limit is 2 MB when uploading from the mobile app and 50 MB from desktop, so FileBelow targets 2 MB — a thumbnail under 2 MB is accepted by both.
A thumbnail that fails to upload leaves the video showing an auto-generated frame, which is usually the worst three seconds of it.
How FileBelow applies them
Choosing this destination sets every rule above at once. After processing, the result panel shows one line per rule with a pass or fail beside it, so you can see that the file genuinely complies rather than hoping it does.
Where the specification sets a minimum size rather than an exact one, FileBelow keeps as much resolution as it can while meeting the other rules, and never scales below the stated minimum.