Free YouTube tool
YouTube Thumbnail Resizer
Crop any image to the 3840 x 2160 YouTube recommends for a video thumbnail, or 2160 x 3840 for a Short, and download it ready to set on your video.
Last updated: 2026-10-25
The YouTube thumbnail help page recommends 3840 x 2160 at 16:9 for a video, at least 640 pixels wide, JPG or PNG. Shorts thumbnails flip that to 2160 x 3840 at 9:16, at least 640 pixels tall. From a computer the file can be up to 50 MB. From the YouTube mobile app, a video thumbnail is capped at 2 MB.
This resizer crops your image to either shape, so a frame grab or a design made at another ratio fits without being stretched. Custom thumbnails need a verified YouTube account, so verify the channel before you count on setting one.
It runs in your browser and nothing is uploaded. When Postify publishes a video it sets your cover image as the thumbnail, fitted to 1280 pixels on the long edge and under 2 MB. Once the thumbnail is ready, plan the video around it and schedule the upload.
Size to export
Pick the image you are making. The preview and the download follow it.
Your image never leaves your browser. The crop and the export both run on your device, and nothing is uploaded to us. HEIC photos straight from an iPhone only decode in Safari, so export a JPEG copy first if yours will not open.
Preview
YouTube video thumbnail, 3840 x 2160 px
Drop an image above to see it cropped to this size.
Focus point
What every crop stays centered on when the shapes do not match.
Focus: Center
Export format
0.85 is the safe default. Push to 0.95 for images with text, drop toward 0.7 only when you are fighting a tight file size cap.
Re-encoding through canvas also drops the EXIF block, so the file you download carries no GPS coordinates, camera model or timestamp.
Sizes at a glance
The numbers each platform publishes, read from its own help pages.
YouTube video thumbnail
| Upload at | 3840 x 2160 px, 16:9 |
|---|---|
| Minimum | 640 px wide |
| Max file size | 50 MB, 2 MB from a phone |
| File types | JPG, PNG |
| Shown as | Rectangle |
SourceChecked on 2026-10-25
YouTube Shorts thumbnail
| Upload at | 2160 x 3840 px, 9:16 |
|---|---|
| Minimum | 640 px tall |
| Max file size | 50 MB |
| File types | JPG, PNG |
| Shown as | Rectangle |
SourceChecked on 2026-10-25
Tips
- Export JPG if you will set the thumbnail from your phone. The YouTube mobile app caps video thumbnails at 2 MB, against 50 MB from a computer.
- Do not go below the minimum. A video thumbnail has to be at least 640 pixels wide, and a Shorts thumbnail at least 640 pixels tall.
- Make a vertical version for Shorts rather than reusing the 16:9 one. A 9:16 frame cut from a landscape design keeps only a narrow strip of the middle.
Frequently asked questions
What size is a YouTube thumbnail?
3840 x 2160 pixels at 16:9 for a video, at least 640 pixels wide, in JPG or PNG. Shorts thumbnails are 2160 x 3840 at 9:16, at least 640 pixels tall. The file can be up to 50 MB from a computer, and a video thumbnail set from the mobile app is capped at 2 MB.
Why can I not upload a custom thumbnail?
Custom thumbnails need a verified YouTube account. If the option is missing, verify the channel first, then check that the file is JPG or PNG and inside the size limit.
Does Postify set the thumbnail when it publishes my video?
When Postify publishes a video it sets your cover image as the thumbnail, fitted to 1280 pixels on the long edge and under 2 MB. Custom thumbnails still need a verified YouTube account.
Is my image uploaded anywhere?
No. The image is cropped with canvas inside this tab and the result goes to your downloads folder. Nothing is sent to Postify or YouTube by this tool.
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