YouTube Thumbnail Size (2026): The New 3840 x 2160 Spec

Updated October 2026. Specs checked against YouTube’s Help Center on October 15, 2026.

YouTube thumbnail size (2026): 3840 x 2160 pixels, 16:9, JPG or PNG, under 50 MB on desktop or 2 MB on mobile. Minimum width 640 pixels. Shorts: 2160 x 3840 at 9:16.

That is the current recommendation on YouTube’s Add custom thumbnails help page, which we read on October 15, 2026. Most thumbnail guides still say 1280 x 720 and 2 MB. Both numbers come from the old version of that page. YouTube replaced them in March 2026, and by mid-September it had added a separate spec for Shorts.

Below: the full spec in one table, exactly what changed and when, where the duration badge covers your design, and a step-by-step for making a thumbnail that clears every limit.

What size should a YouTube thumbnail be?

These are the YouTube thumbnail dimensions, resolution and file limits the Help Center lists today, for each kind of upload.

	Videos	Shorts	Podcast playlists
Recommended resolution	3840 x 2160 px	2160 x 3840 px	Not stated
Minimum	640 px wide	640 px tall	Not stated
Aspect ratio	16:9	9:16	1:1
Formats	JPG or PNG	JPG or PNG	JPG or PNG
Max file size, desktop	50 MB	50 MB	50 MB
Max file size, mobile	2 MB	Desktop only	10 MB

The page’s own wording, as of October 15, 2026: “Have a resolution of 3840 x 2160 pixels for videos and 2160 x 3840 for Shorts, with a minimum width of 640 pixels for videos and a minimum height of 640 pixels for Shorts.” Directly above that, YouTube says your custom thumbnail “should be as large as possible,” because it doubles as the preview image in the embedded player.

Two things the table can’t show. First, custom thumbnails need a verified account; phone verification is what unlocks them, along with uploads longer than 15 minutes and live streaming (YouTube Help: Verify your account). Second, every custom thumbnail has to follow the Community Guidelines. Thumbnails with nudity, hate speech, violence or dangerous content can be rejected and earn a strike, and repeat offenses can cost you custom thumbnail privileges for 30 days.

What changed: the old spec vs the new one

We compared archived copies of the help page on the Wayback Machine to pin down when the numbers moved. The resolution change landed between the March 11 and March 12, 2026 captures. The Shorts spec and the format change appear in the September 18, 2026 capture and not in the August 10 one.

	Old spec (until March 2026)	Current spec (October 2026)
Resolution	1280 x 720	3840 x 2160 (videos), 2160 x 3840 (Shorts)
Minimum	640 px wide	640 px wide (videos), 640 px tall (Shorts)
File size	Under 2 MB for videos, 10 MB for podcasts	50 MB on desktop; 2 MB on mobile (10 MB for podcasts)
Formats listed	JPG, GIF or PNG	JPG or PNG
Shorts	No separate size	Own size, 9:16, desktop-only upload

So the “1280 x 720, under 2 MB” rule isn’t wrong in the sense that YouTube will reject it. A 1280 x 720 JPG is still 16:9 and twice the minimum width. It’s just out of date as advice. YouTube now asks for three times the width and three times the height (nine times the pixels), and gives desktop uploads 25 times the file size room to carry them.

Not every tool has caught up. One example: a thread on the OBS forum reports that OBS Studio’s built-in YouTube live event dialog still enforces 1920 x 1080 and 2 MB (OBS forum). If a third-party uploader rejects your 4K file, upload the thumbnail in YouTube Studio instead.

Do you need a 3840 x 2160 thumbnail?

Not strictly. Make it anyway when you can. YouTube’s instruction is “as large as possible,” and a large master file costs you nothing on desktop, where the limit is 50 MB.

Where it gets awkward is the phone. A 3840 x 2160 PNG with photos and gradients will often be bigger than 2 MB, which is the mobile limit for video thumbnails. Three ways around that:

1. Upload from a computer. The 50 MB desktop limit fits any reasonable 4K image.
2. Export a JPG for phone uploads. JPG compresses photographic thumbnails far more than PNG does.
3. Keep a 1920 x 1080 copy. Still 16:9, still three times the minimum width, and much easier to fit under 2 MB.

Design at 3840 x 2160, export the size each upload path can take, and you’re covered.

YouTube Shorts thumbnail size

Shorts thumbnails are 2160 x 3840 pixels at 9:16, minimum 640 pixels tall. The rules around them are stricter than for regular videos:

• Computer only. YouTube says custom Shorts thumbnails “are currently only available to add in YouTube Studio on a computer.” The path is Studio, then Content, then the Shorts tab, then the Short’s edit page.
• Verified accounts only. Same verification as regular custom thumbnails.
• No A/B testing. YouTube’s title and thumbnail test doesn’t support Shorts (YouTube Help: A/B test titles & thumbnails).

One more trap: if you upload a vertical video with a 16:9 custom thumbnail, YouTube swaps in an auto-generated 4:5 thumbnail on the home, explore and subscriptions pages. Your 16:9 image still shows in the watch feed, watch history and on non-mobile platforms. If your vertical videos keep showing frames you didn’t pick, that’s usually why. More on making Shorts in our guide to AI tools for YouTube Shorts.

Thumbnail safe zones: where YouTube covers your design

YouTube doesn’t publish an official safe-zone diagram for thumbnails, so treat this section as practice, not spec.

On most surfaces YouTube stamps the video length in the bottom-right corner of the thumbnail. On videos a viewer has partly watched, a progress bar runs along the bottom edge. Anything you put in that corner (a face, a price, the last word of your text) risks sitting under a black timestamp box.

A safe layout looks like this:

• Keep text and faces out of the bottom-right corner.
• Leave a little breathing room along the bottom edge for the progress bar.
• Put the main subject in the left or center of the frame.
• Check the thumbnail at phone size before you upload. If you can’t read it at the width of your thumb, it’s too small.

For Shorts, the same logic applies to the bottom of the 9:16 frame, where the feed layers the title and channel name over the video.

How to make a YouTube thumbnail, step by step

YouTube only specifies the file. Whether anyone clicks comes down to the design, so here’s the whole process, from blank canvas to live thumbnail.

1. Set up the canvas

Create a 3840 x 2160 pixel canvas (2160 x 3840 for a Short). Every common editor has a custom size option; if yours has a “YouTube thumbnail” preset, check that it isn’t still the old 1280 x 720.

2. Decide what the image promises

Write down, in a few words, what the video delivers. The thumbnail and the title should make that promise together without repeating each other. If the title says “I Tried Every Budget Airline,” the thumbnail doesn’t need those words again. It needs the reaction, the cramped seat, the price.

3. Pick one or two subjects

A face with a clear expression, an object, a before-and-after. One or two things, big, with nothing important cut off at the edges. Crowded thumbnails turn to mush at phone size.

4. Push the contrast

The subject has to separate from the background. Bright subject on dark background, or the other way around. Avoid colors that blend into YouTube’s own interface in light or dark mode.

5. Use few words, or none

If you add text, keep it to about three big words that add something the title doesn’t say. Put them in the top or left of the frame, clear of the duration badge.

6. Export the right file

Export JPG or PNG. Under 50 MB if you’re uploading from a computer, under 2 MB from a phone. GIF is no longer on YouTube’s list, so don’t rely on it.

7. Upload in YouTube Studio

Go to Studio, then Content, open the video, and under “Thumbnail” click Upload file. Save. For Shorts, use the Shorts tab, on a computer.

8. Test it against an alternative

If your channel has advanced features, YouTube Studio can run an A/B test on up to three titles and thumbnails. YouTube picks the winner by watch time share, not click-through rate, and shows the winner to everyone when the test ends. If there’s no clear winner, the first one you uploaded stays. Changing the title or thumbnail mid-test stops the test.

Make thumbnails in TubeGen

TubeGen is the all-in-one YouTube platform built on the AI models creators already use. Its Thumbnail Studio handles steps 2 to 5 above inside the same project as the video.

• Start from the project. A Project Based thumbnail uses the video’s title and script for context, so the image matches what the video says.
• Use templates. Lock a layout you like, from the public library or your own, and fill its slots with your characters, objects and exact text. You can turn any YouTube thumbnail, upload or past generation into a template.
• Score before you publish. Analyze grades a thumbnail out of 100 on four bars: Subject, Color & Contrast, Title Alignment and Text. It flags things like a subject that won’t read at phone size or more than three words of text. Improve redraws any thumbnail scoring 85 or below.
• Pick a winner, then publish. Compare puts two thumbnails side by side, and the YouTube upload dialog lets you choose any thumbnail from your library for the video.

On size: TubeGen’s docs don’t state a fixed pixel size for Thumbnail Studio downloads, so check the dimensions of the file before you upload it to Studio by hand. If you upload a thumbnail of your own through TubeGen’s YouTube publish dialog instead, it takes a JPG or PNG up to 10 MB, and the docs recommend 1280 x 720 there. That clears YouTube’s minimum easily.

The thumbnail also sits next to the rest of the video. TubeGen writes the script, voiceover, visuals and soundtrack for videos up to 2 hours long, and the video editor exports up to 90 minutes, so the title from the AI title generator and the thumbnail are built from the same project. For a deeper look at the thumbnail tool against other AI options, see our AI YouTube thumbnail generator guide.

Quick checklist before you upload

• 3840 x 2160 (or at least 640 px wide) for videos; 2160 x 3840 for Shorts
• 16:9 for videos, 9:16 for Shorts, 1:1 for podcast playlists
• JPG or PNG
• Under 50 MB from a computer, under 2 MB from a phone
• Account verified
• Nothing important in the bottom-right corner
• One or two subjects, readable at phone size
• Text of about three words or fewer, adding to the title
• Follows the Community Guidelines
• A second version ready for an A/B test

Why the thumbnail matters this much

Your thumbnail and title are the first thing a viewer judges, and in an A/B test YouTube measures them by how much watching follows the click. A thumbnail that overpromises can win impressions and lose the test. Build the image around what the video actually delivers, and it will hold up under the watch-time metric YouTube uses to choose. If you’re working on the bigger picture, our guide on how to grow your YouTube channel covers what comes after the click, and how to make a YouTube video walks through the full production process.