YouTube Thumbnail Size: Dimensions, Aspect Ratio & Common Mistakes

A custom thumbnail is the still image people see before they click your video. It appears in search results, on your channel, in suggested videos and in the embedded player, so it needs to read well both large and very small.

YouTube thumbnail size at a glance

Only the file-size limits are firm limits. The shape, size and format are YouTube's recommendations, which means an image outside them may still upload but is more likely to look soft or be shown with bars.

Why the 16:9 shape matters

A 16:9 thumbnail is 16 units wide for every 9 units high, the same shape as a standard landscape video player. Width ÷ height comes to about 1.778.

All of these are exactly 16:9, so any of them fits the thumbnail frame without bars or cropping:

You can check any pair of numbers with the Aspect Ratio Calculator. For more on how 16:9 compares with the squarer 4:3 shape, read 16:9 vs 4:3.

Correct and incorrect thumbnail shapes

The most common thumbnail problem is starting from an image that isn't 16:9, such as a 4:3 screenshot or a square graphic. There are three ways to make it fit, and they are not interchangeable:

Cropping fills the frame but loses some of the picture. Padding keeps everything but adds bars, which look small and empty in a thumbnail. Stretching changes the shape of faces and text, so it's best avoided. How to make a picture fit without cropping covers padding options in more detail.

File size: phone vs computer

YouTube's limit depends on where you upload from: 2 MB for video thumbnails from a phone, and 50 MB from a computer. A detailed 3840 × 2160 image can easily be larger than 2 MB, so if you upload from the YouTube app you may need to save a smaller JPG or reduce the pixel size.

How to make a YouTube thumbnail, step by step

1. Create a 16:9 canvas, for example 1920 × 1080 or 3840 × 2160.
2. Place the main subject and any text away from the very edges, and keep text large enough to read at small sizes.
3. Check the bottom-right corner: in current layouts YouTube often shows the video length there, so avoid putting key text in that spot.
4. Export as JPG or PNG.
5. Check the file size against the 2 MB phone limit if you upload from the app.
6. Run the file through the YouTube Thumbnail Checker to confirm the shape, width and file size before uploading.

The position of the video-length label is an observation of how YouTube displays thumbnails, not a published specification, and YouTube can change its layout.

Common mistakes

• Using a vertical or square image. The thumbnail frame is 16:9, so other shapes get bars or are cropped.
• Going below 640 px wide. Small images look blurry on large screens and fall below YouTube's minimum.
• Upscaling a small screenshot. Enlarging a 640 px image to 3840 px doesn't add real detail. See how to check whether an image is high resolution enough.
• Exceeding 2 MB on a phone. Large files upload from a computer but can fail in the app.
• Small text. Thumbnails are often shown only a few centimetres wide, so fine text becomes unreadable.

Frequently asked questions

What is the best YouTube thumbnail size?

YouTube recommends making it as large as possible at 16:9, giving 3840 × 2160 as an example. 1920 × 1080 and 1280 × 720 are common working sizes with the same shape.

Is 1280 × 720 still a good thumbnail size?

Yes. It's exactly 16:9 and well above the 640 px minimum width. A larger size gives more detail on big screens.

Do Shorts use the same thumbnail rules?

Not quite. YouTube suggests 2160 × 3840 (9:16) for Shorts thumbnails, with a minimum height of 640 px, and Shorts thumbnails can currently only be added from a computer, where the 50 MB limit applies. This guide covers the 16:9 video thumbnail; vertical framing is covered in the 9:16 aspect ratio guide.

Can I use a PNG?

Yes. YouTube names JPG and PNG as examples of suitable formats. PNG files are often larger, so watch the 2 MB phone limit.

Promoting the same video elsewhere? See TikTok image sizes for vertical content and Facebook image sizes for covers and Stories.

Key takeaways

• Use 16:9, as large as practical; 3840 × 2160, 1920 × 1080 and 1280 × 720 all fit.
• The minimum width is 640 px.
• File limits are 2 MB from a phone and 50 MB from a computer.
• Crop or pad non-16:9 images; don't stretch them.