Updated July 29, 2026
YouTube Thumbnail Specs Reference
YouTube thumbnail checks depend on how you upload. Studio desktop guidance and YouTube Data API upload limits are not identical, so check the target before compressing.
Thumbnail upload checks
| Target | Spec | Value |
|---|---|---|
| Studio desktop | Preferred resolution | 3840 x 2160 px |
| Studio desktop | Minimum width | 640 px |
| Studio desktop | Common player ratio | 16:9 |
| Studio desktop | File-size limit | 50 MB |
| Mobile video thumbnail | File-size limit | 2 MB |
| YouTube Data API | File-size limit | 2 MB |
| YouTube Data API | Accepted MIME types | image/jpeg, image/png, application/octet-stream |
Check the upload pathA thumbnail that is fine in YouTube Studio desktop may still be too large for the YouTube Data API thumbnail upload endpoint.
References
Questions
Is 1280 x 720 still usable for YouTube thumbnails?
It is still 16:9 and above the minimum width, but YouTube's current Help guidance prefers a larger 3840 x 2160 image.
Why does the API still say 2 MB?
The YouTube Data API thumbnail upload endpoint lists its own media upload constraints, including a 2 MB maximum file size.