YouTube Thumbnail Size Checker & Resizer (FREE TOOL)
Drop your thumbnail in, see how it measures up to YouTube, and download it at the size you need. The file never leaves your browser.
Upload thumbnail
Size
The size feeds show. It stays under the 2 MB phone limit.
Fill the frame
Format
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— —
— · Shaded: where YouTube prints the video length.
Built and checked by Marián Cabadaj. Last checked September 2026.
What the sizes here come from
YouTube Help, Add video thumbnails for the 3840 x 2160 and 2160 x 3840 sizes, the 640 pixel minimum width, JPG or PNG, and the 2 MB phone and 50 MB computer limits.
The examples on this page were made by the same code the tool runs.
The short answer
- A YouTube thumbnail is 16:9. YouTube now asks for 3840 x 2160, with a minimum width of 640 pixels (YouTube Help).
- 1280 x 720 is still the size most feeds show, and it stays well under the 2 MB limit for uploads from a phone.
- A Shorts thumbnail is 9:16. YouTube asks for 2160 x 3840. The tool makes 1080 x 1920, the same shape.
- Keep faces and words out of the bottom right. YouTube prints the video length there.
Get Selzee's guides in your Google results.
Add Selzee as a preferred sourceFree YouTube Thumbnail Size Checker
A YouTube thumbnail size checker answers a question a size guide cannot: not what the number is, but what happens to your file. Drop a thumbnail in and the browser reads its size, compares it to 16:9, and shows it at the size you pick. Nothing is uploaded and no account is needed.
The number itself has moved, which is the other reason to check. YouTube now recommends 3840 x 2160, and most of the pages ranking for this term still print 1280 x 720 as the answer. That figure is not wrong, it is the floor, and on a television the difference shows.
Every YouTube size the tool makes
| Size in pixels | Shape | Use it for | |
|---|---|---|---|
| 1280 x 720 | 1280 x 720 | 16:9 | The size feeds show. It stays under the 2 MB phone limit. |
| 4K | 3840 x 2160 | 16:9 | The size YouTube asks for, for televisions. Use it only when your image is at least that big. |
| Shorts | 1080 x 1920 | 9:16 | A Shorts thumbnail. YouTube asks for 2160 x 3840, the same shape. |
Source: YouTube Help. For a channel banner, use the YouTube banner size checker. Verified 2026-09-30.
Four thumbnails, before and after
Four ads made with Selzee, each turned into a YouTube thumbnail. Three use Fit, so no word is lost. One uses Crop.
How the Thumbnail Checker Works
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Drop the file in
Choose a file, drag it onto the box or paste a screenshot. The browser reads its width and height, which is all the arithmetic needs, so nothing is sent anywhere.
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Read the check
One line says whether your file is already 16:9 (or 9:16 for Shorts) and whether it clears the 640 pixel minimum. Another says how big the file will be, against the 2 MB phone limit and the 50 MB computer limit.
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Pick a size, crop or fit, download
1280 x 720 is selected first. Switch to 4K or Shorts. Crop fills the frame and you drag to choose what stays; Fit keeps the whole image. The duration badge is shaded on the preview, never on the file.
Crop or fit: the one choice that matters
Crop makes the image big enough to cover the whole frame and cuts off what hangs over the edge. The thumbnail is full bleed. Use it for a photo or a video still with space around the subject.
Fit makes the image small enough to sit whole inside the frame and fills the empty band. Use it for a poster, a slide or an ad with words near the edge. A crop would cut the letters.
YouTube itself crops anything that is not 16:9 from the middle, and you do not choose the framing. Choosing Crop here lets you drag it where you want before you upload.
Why Check a Thumbnail Before You Upload
A thumbnail is the only part of a video that competes in the feed, and it is the part most likely to be quietly altered on the way in. Two things go wrong, and neither is visible in your design tool.
The rejection is usually the file, not the dimensions
The limit is 2 MB in the phone app and 50 MB from a computer, and YouTube asks for JPG or PNG. A webp export decodes perfectly in your browser and is refused on upload, which is the failure with no error message attached to it.
The crop is centred and you do not choose it
Anything that is not 16:9 is cut to fit from the middle. On a design with a face to one side, that is the face.
The recommendation moved and the guides did not
Most pages answering this question still print 1280 x 720. Exporting to that today gives you a thumbnail that holds up in a feed and falls apart on a 4K panel.
Why the Recommended Size Moved, and Why Most Pages Missed It
For years the answer was 1280 x 720, and it was right. A thumbnail was a small tile in a feed on a phone, and 720p carried everything that tile could show. YouTube has since raised the recommendation to 3840 x 2160, because a thumbnail is no longer only that tile: it is the poster frame on a television, the still on a watch page, the preview inside an embed on somebody else's site. Fine text and small faces that held together at 1280 wide come apart on a 4K panel.
The reason so many pages still print the old number is the reason this one keeps its figures in a single file and dates them. A spec typed into a sentence has no way of noticing that it changed. It sits there collecting links and looking authoritative, and the more links it collects the longer it survives being wrong. Treat 1280 x 720 as the floor, export at 4K, and let the file size be the thing you manage. The same trap catches every platform, which is why the table of every surface carries the date each figure was last read off the platform itself.
How to Export One That Survives
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Design at 3840 x 2160
Start on the 4K canvas rather than scaling up at the end. Upscaling a 1280 wide design gives you a 4K file with 720p detail: the size of the new spec and the sharpness of the old one.
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Keep the face and the last word out of the bottom right
The duration badge lands there in every feed placement. The tool shades it on your own frame.
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Export as JPG at around quality 80
The same frame as a JPG lands far inside the limit with no loss visible at any size anyone will view it, and JPG is one of the two types YouTube names.
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Use PNG only for flat colour and hard type
There it compresses better than JPG and keeps the edges clean. That is the one case where PNG is both smaller and sharper.
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Run the finished file through the checker
Before you find out on the watch page.
Who This Checker Is For
Creators posting weekly
The thumbnail is the whole click decision and there is no design team to catch a bad export. One check before upload.
Small teams with a template
A template fixes the layout and not the export settings. This catches the webp export and the oversized PNG that will be refused.
Anyone whose upload was rejected
It is almost always the file type or the size rather than the dimensions, and the checker says which.
What the Checker Tells You
Every file returns the same four things, so the answer has the same shape whichever file you drop in.
The check
Your file against YouTube: already 16:9 (or 9:16 for Shorts), a different shape, or under the 640 pixel minimum.
The file size
The real size of the file you will download, against the 2 MB phone limit and the 50 MB computer limit.
The duration badge
Shaded on your own frame, bottom right, where YouTube prints the video length. Only on the preview.
The fixed file
A JPG or PNG at exactly 1280 x 720, 3840 x 2160 or 1080 x 1920, cropped or fitted the way you chose.
YouTube Thumbnail Size: FAQ
What size should a YouTube thumbnail be?
Why does YouTube reject my thumbnail?
Does a bigger thumbnail look sharper?
What aspect ratio do YouTube thumbnails use?
What file formats does YouTube accept?
What size is a YouTube Shorts thumbnail?
Where should text go on a YouTube thumbnail?
Is my image uploaded anywhere?
When the Thumbnail Is Right and the Video Still Does Not Land
Getting to 3840 x 2160 is an export setting, and it takes one afternoon to fix forever. The harder problem is knowing which hook to put on the frame this week, and the week after. Selzee reads your comments, reviews and post results, turns them into concepts worth making, and learns from what each one does.
- A file that arrives the way you made it
- Type and logos that are still visible after the platform draws its own interface
- One export instead of three attempts
- A check that takes a second, on your own device, with nothing uploaded
Keep exploring
See the 2560 x 1440 crop and the 1235 x 338 safe area YouTube keeps on every device, drawn on your own banner. Nothing is uploaded.
Paste a YouTube link and download every thumbnail size YouTube stores, up to 1280 x 720. Nothing is uploaded.
Free X image resizer. Pick 16:9, square, 4:5 or header, fit the whole photo or crop it, and download a JPG or PNG under the 5 MB limit. Nothing is uploaded.
Free Facebook image resizer. Pick feed, square, link, story or cover, fit the whole photo or crop it, and download a JPG or PNG at the exact size. Nothing is uploaded.
Start Making Thumbnails Worth the Click
The checker is free, with no signup and no credit card. When you want the idea on the thumbnail to come from your own audience rather than a guess, start free.
Get started for free