Why thumbnails look blurry
Small source images, heavy compression, and enlarged text can lose clarity after YouTube scales the thumbnail across different screens. See why YouTube thumbnails look blurry.
YouTube thumbnail requirements
YouTube thumbnail dimensions guide and checker
Check the image size, 16:9 shape, file limit, format, and small-screen readability before you upload a custom thumbnail.
Check your YouTube thumbnailImages never leave your device.
Current thumbnail requirements
- Recommended size
- 3840 x 2160 pixels
- Minimum width
- 640 pixels
- Aspect ratio
- 16:9
- Mobile file limit
- 2 MB for video thumbnails
- Desktop file limit
- 50 MB
- Common formats
- JPG, GIF, or PNG
YouTube recommends making the image as large as possible. The upload limit differs by device, so a file that works on desktop may still be too large when uploading from a phone. For upload limits, see the YouTube thumbnail file size guide.
safe area
16:9
Check the small-screen view
Faces, products, and short text should remain clear when the thumbnail appears as a small card in mobile feeds.
Need composition guidance? See the YouTube thumbnail safe zone guide. For a short pre-upload checklist, use the YouTube thumbnail best practices guide.