Home › Create & format › YouTube Thumbnail Size Checker
YouTube Thumbnail Size Checker
Choose a thumbnail image to see whether its dimensions, 16:9 ratio, file size and format match what YouTube recommends. Your image stays on your device.
Free, no sign-up, runs in your browser. Updated 2026-11-09.
YouTube thumbnail requirements
YouTube's help pages recommend a custom thumbnail of 1280 × 720 pixels (minimum 640 pixels wide), in a 16:9 aspect ratio, saved as JPG, GIF or PNG, and under 2 MB. This checker compares your file with those numbers so you find problems before you upload, not after.
| Item | Recommended |
|---|---|
| Resolution | 1280 × 720 px |
| Minimum width | 640 px |
| Aspect ratio | 16:9 |
| File size | Under 2 MB |
| Formats | JPG, GIF, PNG |
Requirements can change, and your account may need to be verified to upload custom thumbnails. Check YouTube Help for the current rules.
Fixing a thumbnail that fails
- Wrong ratio or size: resize and crop it with the social image resizer.
- Over 2 MB: export as JPG at a slightly lower quality, which is usually much smaller than PNG.
- Looks blurry: start from a 1280 × 720 or larger design instead of enlarging a small image.
Design tips
- Keep text large and short, since thumbnails are small on phones.
- Leave the bottom-right corner clear, where the video length badge appears.
- Use strong contrast so the thumbnail reads at a glance.
- Make the thumbnail match the video, so viewers are not misled.
Need sizes for other platforms? See the social media image sizes and limits guide.
How to use this youtube thumbnail size checker
- Press the file picker and choose your thumbnail from your device.
- Wait a moment while the browser reads the image. Nothing is uploaded.
- Read each line: a tick means it meets the recommendation, a warning means it does not.
- Fix any warnings and check the file again before uploading it to YouTube Studio.
Frequently asked questions
What size is a YouTube thumbnail?
YouTube recommends 1280 × 720 pixels with a 16:9 aspect ratio and a minimum width of 640 pixels.
What is the maximum thumbnail file size?
YouTube Help lists a limit of 2 MB for custom thumbnails. JPG files are usually smaller than PNG.
Is my image uploaded anywhere?
No. The check runs in your browser and the image never leaves your device.
Which formats can I use?
JPG, GIF and PNG are the formats YouTube lists for custom thumbnails.
Does a pass guarantee YouTube will accept it?
No. This checks size, ratio, file size and format only. YouTube may still reject a thumbnail that breaks its policies.