YouTube Thumbnail Resizer

What YouTube asks for

YouTube Help's page "Add video thumbnails" (checked 16 October 2026) says a custom thumbnail should:

• be 16:9 and "as large as possible", with a resolution of 3840 × 2160 pixels and a width of at least 640 pixels;
• be a JPG or PNG file;
• stay under 2 MB when you add it in the YouTube app on a phone, or under 50 MB in YouTube Studio on a computer.

For years the same page recommended 1280 × 720, and that is still the size most channels use. It looks sharp in search results and on phones and makes small files. Choose 1920 × 1080 or 3840 × 2160 when many of your viewers watch on large screens or TVs. Only verified YouTube accounts can add custom thumbnails.

Crop to fill or show the whole image

Every thumbnail made here is exactly the size you choose. There are two ways to get there:

• Crop to fill (the default) scales the image until it covers the whole 16:9 frame and cuts off what sticks out, keeping the centre. A 4000 × 3000 photo loses 375 pixels at the top and 375 at the bottom, and the remaining 4000 × 2250 is scaled to 1280 × 720.
• Whole image scales the picture until it fits inside the frame and fills the empty bands with a colour you pick. Use it for square logos, portrait photos or screenshots where nothing may be cut off.

Images smaller than the chosen size are enlarged, which makes them soft; the list marks them "Enlarged". For a sharp thumbnail, start with an image at least as large as the size you choose.

Staying under 2 MB

A 1280 × 720 JPG is usually a few hundred KB. A 3840 × 2160 thumbnail of a detailed photo can be larger than 2 MB, and the YouTube app then refuses it. With "Keep each image under 2 MB" switched on, the tool first saves the image at the quality you set. If the file is too large, it tries lower JPG qualities and keeps the highest one that fits, and the list shows it, for example "84% quality". PNG is lossless, so its size cannot be reduced this way; that is why JPG is the default here. If you switch the option off, files over 2 MB are marked "Over 2 MB", which is fine when you upload from a computer.

Check it small

After resizing, the preview shows your thumbnail with the corner where YouTube shows the video length, next to a copy at the small size used in lists of videos. If the words are hard to read there, use fewer and bigger words.

Privacy

Everything happens in your browser. Your images are not uploaded to our server or to YouTube, and the saved thumbnail contains no EXIF data such as the GPS location.