YouTube Thumbnail Size: Current Specs for Videos and Shorts (2026)

The YouTube thumbnail size is 3840 × 2160 pixels at 16:9 for videos and 2160 × 3840 at 9:16 for Shorts, according to YouTube Help as of 5 November 2026. The minimum is 640 pixels wide for videos and 640 pixels tall for Shorts. Files can be up to 50 MB when you upload on a computer, but only 2 MB on a phone.

If you remember "1280 × 720, under 2 MB" from older guides, you are not alone, and that size still works. It just isn't what YouTube's own page recommends any more. This guide gives you the current numbers, explains where 1280 × 720 still matters, and shows real file sizes from a test we ran so you know which format to export.

What is the correct YouTube thumbnail size in 2026?

Here is everything YouTube states on its custom thumbnails help page, checked on 5 November 2026.

Two details are worth pausing on. The 640 px minimum gives you a 640 × 360 thumbnail at 16:9, which is the smallest file YouTube accepts but not one you should aim for. And the YouTube Data API matches the desktop limit: 50 MB, with JPEG and PNG as the named image types. If your scheduling tool uploads through the API, it should follow the same rule.

Is 1280 × 720 still a good YouTube thumbnail size?

Yes, 1280 × 720 is still a safe floor, even though YouTube Help no longer lists it as the recommended size. It is the same 16:9 shape, and it has one job left that matters: YouTube's A/B test.

The A/B testing help page says that if any thumbnail in a test is below 720p (1280 × 720), every thumbnail in that test gets downscaled to 480p (854 × 480). So a single small file drags down all of your variants.

A simple way to choose:

3840 × 2160 holds nine times the pixels of 1280 × 720. That only helps if those pixels contain real detail. Stretching a small file to 4K in a basic editor makes it bigger, not sharper.

JPG or PNG: which keeps a thumbnail under the limit?

JPG is the safer export, especially if you upload from a phone. Most guides simply repeat "under 2 MB", so we measured it. On 5 November 2026 we resized three existing images from our own storage to each size and saved them with Python's Pillow library.

What this shows:

• Every PNG at 3840 × 2160 went over the 2 MB phone limit. They would all be fine on a computer, where the limit is 50 MB.
• PNG at 1920 × 1080 can go either way. Two images stayed under 2 MB and the busiest one reached 3.10 MB.
• JPG at quality 85 stayed under 2 MB at every size. The largest file was 1.16 MB.
• Busy images weigh far more than flat ones. The most detailed of the three was about two to three times heavier than the others in the same format.

Treat these as a guide rather than a guarantee. It was a small test of three images, and the 4K versions were enlarged from files no wider than 1600 px. A true 4K photo holds more detail, so expect a larger file than the table shows.

Older guides also list GIF and BMP. YouTube Help names only JPG and PNG, as examples, and the API names only JPEG and PNG, so use one of those two.

What size is a YouTube Shorts thumbnail?

A Shorts thumbnail should be 2160 × 3840 pixels at 9:16, with a minimum height of 640 pixels. At that minimum the file would be 360 × 640. There are three rules that catch people out:

1. You need a computer. YouTube says custom Shorts thumbnails can currently only be added in YouTube Studio on a computer, under Content, then Shorts.
2. Your account must be verified. This is the same requirement as regular custom thumbnails.
3. Don't use a 16:9 image on vertical videos. YouTube says vertical videos with 16:9 custom thumbnails are replaced by an auto-generated 4:5 thumbnail on the home, explore and subscription pages. Your design simply won't show there.

Shorts are also left out of A/B testing, so you can't compare options the way you can on a regular video. If you are building a Shorts channel from scratch, our AI video generator for YouTube Shorts page covers the vertical format.

Where does the timestamp sit, and what is the safe area?

The video length appears in the bottom-right corner of a regular video thumbnail, on top of your image. On videos someone has partly watched, a progress bar also runs along the bottom edge.

YouTube doesn't publish a safe area for thumbnails. Its help page doesn't mention the timestamp at all, and neither does it give a size for it. So the numbers below are our own rule of thumb, not an official spec: keep faces, text and logos out of the bottom-right 20% of the width and 15% of the height.

Put your main subject in the left or centre, and any text at the top or left. For Shorts, keep the important part near the centre of the frame, because the surfaces that show them vary.

Why can't I upload a custom YouTube thumbnail?

The usual cause is that your account isn't verified. YouTube says you can pick from auto-generated options, or upload your own if your account is verified. Its feature access page says phone verification unlocks intermediate features, and only the primary channel owner can do it.

The path is YouTube Studio, then Settings, Channel, Feature eligibility, Intermediate features, and Verify phone number. YouTube's thumbnail page doesn't say which feature tier it means by "verified", so if the option still doesn't appear after phone verification, check the Feature eligibility tab.

Other common causes:

• File too large on mobile. A PNG can easily pass 2 MB, as the test above shows. Export as JPG or upload from a computer.
• Daily limit reached. YouTube says to try again after 24 hours if you see the daily custom thumbnail limit error.
• The change hasn't shown yet. YouTube notes that it can take time for a new thumbnail to appear.
• The image was rejected. Thumbnails must follow the Community Guidelines, and YouTube says a rejected thumbnail can lead to a strike.

How do you make a thumbnail at the right size?

You can do this with any design tool. Here is the route on Kenerate AI, which needs a free sign-in and gives you 25 free credits on sign-up.

1. Generate the image. Open the AI thumbnail generator and use the Thumbnail preset in the image studio. It makes four 16:9 variants per click at 1K. For reference, a 1K 16:9 thumbnail on that page measures 1365 × 768, so it clears the 1280 × 720 floor. Put the exact words you want in quotes in your prompt.
2. Fix the shape if you need to. Use the image cropper and choose 16:9 for regular videos or 9:16 for Shorts. Cropping uses no credits. If your photo is too narrow for 16:9, uncrop it to extend the sides instead of cutting the top and bottom.
3. Add your text. The Edit Studio has a YouTube thumbnail canvas at 1280 × 720, with Bold and Reaction templates.
4. Upscale if you want 4K. The AI image upscaler has 2K, 4K and 8K targets. Upscaled files can come out a little larger than the target, which is fine as long as the ratio stays 16:9.
5. Export as JPG. Check that the file is under 2 MB if you plan to upload from your phone.

Doing your channel art at the same time? YouTube banners use a different size and safe area, and our YouTube banner generator lists YouTube's numbers for those.

How do you check a thumbnail before uploading?

Size is only half the job, because your full-resolution design is rarely what viewers see. Shrink your image until it is about as wide as your thumb and look at it on your phone. Then ask three things:

• Can you still read every word?
• Can you tell what the subject is in one glance?
• Is anything important sitting in the bottom-right corner?

If your channel leans comedic, the same test applies to a funny YouTube thumbnail. A joke has to land at that tiny size, so one exaggerated face or one absurd object usually beats a detailed scene with a caption explaining it.

Can you A/B test thumbnails at this size?

Yes, on regular videos. YouTube Studio lets you test up to three titles, thumbnails or combinations of both. The feature is computer only and needs advanced features enabled. It isn't available for Shorts, scheduled live streams, or videos that are private, made for kids or for mature audiences. Premieres are only eligible after they end.

A test can take a few days and should finish within two weeks. YouTube picks the winner on watch time, not click-through rate, so a thumbnail that gets more clicks can still lose. Upload every variant at 1280 × 720 or larger, and don't change the title or thumbnail while the test runs, because that stops it.

Bottom line

For a new thumbnail today, export at 3840 × 2160 if your source has that much detail, and never go below 1280 × 720. Use JPG, keep it under 2 MB if a phone is involved, and leave the bottom-right corner clear. For Shorts, use 9:16 and upload from a computer.

These limits can change, so check the YouTube Help page if you are reading this long after 5 November 2026.