Thumbnail Size Checker
Check YouTube thumbnail dimensions, aspect ratio, and file size locally.
Thumbnail size workspace
Check YouTube thumbnail dimensions, aspect ratio, and file size locally.
Width
Height
File size
Ready
- 3840 x 2160 px is YouTube's preferred current thumbnail resolution; this image is 16:9 but below that preferred size.
Output
16:90 issues50 MB Studio max
Files are processed in your browser. No data is uploaded.
Questions
Does Thumbnail Size Checker upload my image?
No. This tool checks entered dimensions and file size locally; no image is uploaded.
What thumbnail size does it check?
It checks 16:9 thumbnails with at least 640 px width, flags when they are below YouTube's current preferred 3840 x 2160 px size, and separates Studio file-size guidance from the YouTube Data API 2 MB upload limit.
Does Utilumo upload my input?
No. This tool is designed for local browser processing and does not send your input to a server.
Do I need an account?
No. Utilumo tools are built to work without accounts or sign-in.