YouTube Thumbnail Size Checker
Check any image against YouTube's 1280 x 720 spec and resize it to fit. The file is read in your browser and never uploaded.
Drop an image here, or click to choose one
JPG, PNG, GIF or WEBP — nothing leaves your device
Every YouTube image size
| Asset | Size | Ratio | Notes |
|---|---|---|---|
| Video thumbnail | 1280 x 720 | 16:9 | Minimum 1280px wide. Under 2 MB. |
| Shorts thumbnail | 1080 x 1920 | 9:16 | Vertical. Taken from the video frame. |
| Channel banner | 2560 x 1440 | 16:9 | Safe area 1546 x 423 in the centre. |
| Channel profile picture | 800 x 800 | 1:1 | Renders as a circle. |
| Video watermark | 150 x 150 | 1:1 | Under 1 MB, PNG or GIF. |
YouTube wants a thumbnail at 1280 x 720 pixels, in a 16:9 ratio, under 2 MB. Miss the width and YouTube upscales your image and it looks soft next to everything around it. Miss the ratio and it gets cropped or letterboxed in ways you did not choose.
Drop an image in and this checks all four constraints at once, then resizes it correctly if it fails. The file is read locally through your browser's File API and drawn to a canvas — it is never uploaded, and there is no account or credit cost.
How the resize works
Cover, not stretch
The image is scaled until it covers 1280 x 720 and the overflow is cropped from the edges, rather than squashed to fit. A tighter crop is almost always better than a distorted face.
Centred crop
The crop is taken from the centre. If your subject sits hard against one edge, reposition it before resizing rather than after.
Quality
Re-encoded as JPEG at 92% quality, which keeps the result comfortably under the 2 MB ceiling while staying visually indistinguishable at thumbnail scale.
How to use it
- 1
Drop in your image
Select or drag a thumbnail image. It is read locally by your browser and never uploaded.
- 2
Check it against the spec
You get the exact dimensions, aspect ratio, file size and format, each marked pass or fail against YouTube's requirements.
- 3
Resize and download
Convert the image to the correct 1280x720 at 16:9 and download the corrected file.
What this will not do
- It checks dimensions, not design. An image can pass every constraint here and still be unreadable at the size it actually appears — try the Thumbnail Analyzer for that.
- It cannot recover detail that is not there. Resizing a 640-wide image up to 1280 makes the file the right shape, not the right sharpness.
- The centred crop is fixed. For control over what gets cut, crop the image before dropping it in.
- Shorts thumbnails are pulled from the video frame rather than uploaded, so the 1080 x 1920 row in the reference table is for planning your framing, not for an upload.
Common questions
What is the correct YouTube thumbnail size?
1280 x 720 pixels, 16:9 aspect ratio, under 2 MB, in JPG, PNG, GIF or WEBP. 1280 x 720 is the minimum recommended width of 1280px; smaller images are upscaled by YouTube and look soft.
What size are YouTube Shorts?
Shorts are vertical 9:16 — 1080 x 1920 pixels. That is a different spec from a standard thumbnail, and this checker reports both.
Why is my thumbnail blurry on YouTube?
Almost always because the source image is under 1280px wide and YouTube upscaled it, or because heavy JPG compression was applied to fit under 2 MB. The checker flags both cases.
Does the image get uploaded anywhere?
No. The file is read by your browser using the local File API and processed on a canvas element. It never leaves your device and nothing is stored.
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