YouTube thumbnail size (2026).3840 × 2160 at 16:9, up to 50 MB.

What changed in 2026: 4K thumbnails and 50 MB

For years the answer was 1280 × 720 and 2 MB. YouTube announced larger thumbnails in October 2025, and its help page now reads differently: 3840 × 2160 for videos, 2160 × 3840 for Shorts, JPG or PNG, and 50 MB when you upload from a computer. From the phone app the limit is still 2 MB.

• Resolution3840 × 2160 recommended, 640 pixels wide at least, always 16:9 for videos.
• File size50 MB from a computer, 2 MB from the phone app. The API that scheduling tools use moved from 2 MB to 50 MB on September 14, 2026.
• FormatsJPG or PNG. GIF left the list in 2026, and the API only takes JPEG and PNG.
• What YouTube servesSince September 2026 YouTube can serve thumbnails in 1080p, 1440p and 4K for some videos, on top of the smaller sizes it always had.

Most pages that rank for this question still give 1280 × 720 and 2 MB. They were right until 2025.

1280 × 720 or 3840 × 2160: which one to export

Export at 3840 × 2160 when you upload from a computer and your source is large enough: a screenshot of a 4K frame, a photo from a recent camera, a design made at that size. The thumbnail stays sharp on TVs and large screens, where YouTube now serves bigger versions.

Export at 1280 × 720 when you upload from your phone, or when your source is small. It fits the 2 MB limit of the phone app, and upscaling a small picture to 4K doesn't add detail. Don't go below it if you run A/B tests: when any of the thumbnails in a test is under 1280 × 720, YouTube shows all of them at 854 × 480. A 1920 × 1080 thumbnail sits in between and works for both.

Where your thumbnail showsMostly small.

The same image appears on the home page, in search, next to the video being watched, on phones and on TVs, at very different sizes. YouTube doesn't publish them, and it advises making the thumbnail as large as possible because devices differ. The sizes it serves go from 120 × 90 up to 4K. In practice, most people decide whether to click from a picture a few centimetres wide: the small previews under the resizer show your image at those sizes.

The video length is drawn over the bottom-right corner on most of those placements. Keep text and faces out of it. For vertical videos, YouTube replaces a 16:9 custom thumbnail with an automatic 4:5 one on the home, explore and subscriptions pages.

YouTube Shorts thumbnail size

A Shorts thumbnail is 2160 × 3840 pixels (9:16), at least 640 pixels tall. Shorts are square or vertical videos of up to 3 minutes (since October 15, 2024).

• Custom imageUploaded in YouTube Studio on a computer. Launched on July 24, 2026 for YouTube Partner Program creators first.
• A frame from the videoPicked in the YouTube app when you post, or from three suggested frames in Studio on a computer.
• No A/B testsTesting thumbnails isn't available for Shorts.

How to make a thumbnail at the right size

• 1. Start on a 16:9 canvas3840 × 2160 if your photos are large, 1280 × 720 otherwise. Starting at the final size avoids a blurry resize at the end.
• 2. Build it for the smallest viewOne subject, three words at most, large type, nothing in the bottom-right corner.
• 3. Export as JPGHigh quality, sRGB. Check the file is under 2 MB if you'll upload it from your phone.
• 4. Check it smallLook at it a few centimetres wide before you upload. If you can't read it, nobody in search will.

Starting from a photo or a frame of the video instead, the resizer at the top of this page crops it to 16:9, shows it at the small sizes, and exports it under the limit you pick.

File formats, and the "larger than 2 MB" error

YouTube takes JPG or PNG thumbnails. PNG files are much larger for photos: a 1280 × 720 PNG photo can go over 2 MB, and the phone app then refuses it. Three ways around it:

• Save it as JPGAt high quality, a 1280 × 720 JPG is usually a few hundred kilobytes. The resizer above exports JPG and keeps the file under the limit of the size you pick.
• Upload from a computerYouTube Studio on a computer takes up to 50 MB.
• Don't upscaleExporting a small image at 4K makes a heavy file with no extra detail.

How to add a custom thumbnail

Custom thumbnails need a verified account: verifying your phone number unlocks YouTube's intermediate features, and custom thumbnails with them. Then, in YouTube Studio, open the video's details and upload the image under Thumbnail. YouTube limits how many custom thumbnails a channel can upload each day, without publishing the number.

To compare, YouTube's A/B test takes up to 3 thumbnails or titles per video, on a computer, for channels with advanced features. The test runs for up to two weeks and keeps the version with the most watch time, not the most clicks.

Design rules that survive the smallest placement

• Three words at mostText on a thumbnail is read at a few centimetres wide. Large letters, heavy weight, strong contrast.
• One subjectA face or one object, big enough to read at the smallest size. Check it in the small previews under the resizer.
• Keep the bottom-right corner clearThe video length covers it on most placements.
• Match the title, don't repeat itThe title is right next to the thumbnail: the image can say what the title doesn't.

Other YouTube sizes