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YouTube thumbnail size
3840 × 2160 px (16:9), at least 640 px wide, under 2 MB from a phone or 50 MB from a computer
YouTube now recommends thumbnails of 3840 × 2160 pixels, at least 640 pixels wide. Drop in an image, or a video to pick a frame from, and see whether it fits, where the timestamp will sit and how it looks small, then download a copy at exactly the right size. It all runs in your browser.
| Format | Pixels | Ratio |
|---|---|---|
| Video thumbnail 16:9 | 3840 × 2160 | 16:9 |
| Shorts thumbnail 9:16 | 2160 × 3840 | 9:16 |
Official: YouTube Help, YouTube Studio Help (en-IN). Guides (not the platform’s own figures): vidIQ.
Creators upload. Brands review. One thread.
Every video, note and revision stays in one place inside Myah.YouTube thumbnail sizes, with sources
YouTube Help says a custom thumbnail should be as large as possible, because it is also used as the preview image in the embedded player. It recommends 3840 × 2160 pixels with a minimum width of 640 pixels, an image format such as JPG, GIF or PNG, and a 16:9 shape, which it calls the most used in YouTube players and previews. The size limit depends on where you upload from: 2 MB on a phone, 50 MB on a computer. The two smaller export sizes in the checker, 1920 × 1080 and 1280 × 720, are other 16:9 sizes that stay above the 640 pixel minimum. They are offered for convenience and are not YouTube’s figures.
| Format | Pixels | Ratio | Limits YouTube states | Source |
|---|---|---|---|---|
| Video thumbnail16:9 | 3840 × 2160 | 16:9 | At least 640 px wide. JPG, GIF or PNG. Under 2 MB from a phone, under 50 MB from a computer. | YouTube Help (official) |
| Shorts thumbnailVerified channels | 2160 × 3840 | 9:16 | 9:16 recommended for an uploaded file. Added in YouTube Studio on a computer. | YouTube Studio Help (en-IN) (official) |
YouTube’s own pages disagree about Shorts thumbnails. Its English help page says you cannot upload a custom Shorts thumbnail and can only select a frame from the Short, which cannot be changed after upload. The en-GB and en-IN versions (the en-IN page carries an August 2026 date) describe uploading one in YouTube Studio on a computer, for verified accounts. We show the upload format, and say here that you may only see the frame picker.
How the checker works
- Your image’s width, height and file size are read in your browser. For a video, only its width and height are read, because only one frame of it is used. Nothing is sent anywhere.
- Its shape is compared with 16:9 (or 9:16 for a Shorts thumbnail). A match within 1% counts as the same shape. Anything else is cropped or padded by the download.
- Its width is compared with YouTube’s 640 pixel minimum and its 3840 pixel recommendation. Below the minimum is marked “Won’t work”; between the two is marked “Fits with changes”, because it will work but larger is sharper.
- Its file size is compared with both limits, and its type with YouTube’s list. A WebP is accepted here, and the download saves a JPG.
- After you download, the new file’s size is checked against the same limits, so you know if it will upload from a phone.
The timestamp corner
YouTube draws the video’s length over the thumbnail, and vidIQ’s thumbnail guide (July 2025) says it is always in the bottom-right corner, so you cannot avoid it and should plan for it. YouTube Help does not describe the badge, so this is a guide and not a YouTube figure. The badge in the preview is illustrative: it shows where to keep clear, not its exact size. Turn on “Small size” to see the thumbnail at half and a quarter of the preview’s width with the badge on it, so you can check it still reads.
Keep clear
Bottom-right: the badge. Put the headline, the face and any logo in the other three corners or the middle.
Check it small
If the words cannot be read at a quarter of the preview’s width, make them bigger or use fewer of them.
Pick a frame, then design
Load a video, scrub to the frame you want and download it as a 16:9 image. Then add your text on top in your editor.
Thumbnails on vertical videos
YouTube Help has a note for vertical videos: one with a 16:9 custom thumbnail is replaced by an automatically generated 4:5 thumbnail on the home, explore and subscription pages. Your custom thumbnail still appears on the watch feed, in watch history and on non-mobile platforms. The help page does not say how the 4:5 thumbnail is made, so keep the subject in the middle of the frame and do not rely on the edges.
YouTube Shorts size
YouTube Help says a video with a square or vertical aspect ratio and up to three minutes in length, uploaded on or after 15 October 2024, is categorized as a Short. So a Short does not have to be 9:16, but 9:16 fills the screen. For the pixel size, SocialBu’s September 2026 guide recommends 1080 × 1920 as a practical production size, not the only format YouTube accepts, and says YouTube states a maximum resolution of 1080p for Shorts uploads. Both of those are the guide’s words, not YouTube’s, so they are marked as a guide.
| What | Value | Source |
|---|---|---|
| Shape | Square or vertical | YouTube Help (official) |
| Length | Up to 3 minutes (uploaded on or after 15 October 2024) | YouTube Help (official) |
| Video size to use | 1080 × 1920 px (9:16) | SocialBu, 13 Sep 2026 (guide) |
| Thumbnail | 9:16, 2160 × 3840 px, or pick a frame | YouTube Studio Help (en-IN) (official) |
To check a Short’s thumbnail here, choose “Shorts thumbnail 9:16” above and drop in an image, or a video to take the frame from.
Who it’s for
YouTubers and UGC creators
Check a thumbnail before you upload it, and take a clean frame from your video at the right shape and size.
Brands and agencies
Check the thumbnail a creator sends before it goes on your channel, and hand back a copy that meets YouTube’s size and file rules.
Editors and designers
Export once at 3840 × 2160, see whether it still reads at a quarter size, and keep the bottom-right corner clear.
Common mistakes
Text in the bottom-right corner
The video’s length is drawn there, and it always covers part of the thumbnail. Put the words and the face somewhere else, and check it in the preview.
Uploading a 4K PNG from a phone
YouTube’s limit from a phone is 2 MB. A 3840 × 2160 PNG is often bigger, so the upload fails. Upload from a computer, or export a JPG, or pick a smaller size.
Words too small to read at half size
A thumbnail has to work when it is shown small. Switch on “Small size” to see it at half and a quarter of the preview, and make the text bigger until it still reads.
Assuming a vertical video keeps its 16:9 thumbnail
YouTube Help says a vertical video with a 16:9 custom thumbnail gets an automatic 4:5 one on the home, explore and subscription pages. Keep the subject in the middle.
A thumbnail narrower than 640 pixels
YouTube asks for at least 640 pixels of width. The checker marks a smaller image as “Won’t work” so you find out before the upload.
A 16:9 image for a Short
A Shorts thumbnail is 9:16 when you can upload one. A landscape image is cropped or padded to fit, so crop it to 9:16 yourself and choose what stays.
Common questions
What is the best size for a YouTube thumbnail?
YouTube Help recommends 3840 × 2160 pixels with a 16:9 shape, and asks for at least 640 pixels of width. It also says to keep the file under 2 MB when you upload from a phone and under 50 MB from a computer, and to use an image format such as JPG, GIF or PNG.
Is 1280 × 720 still a good YouTube thumbnail size?
It still works: it is 16:9 and well above the 640 pixel minimum width. But YouTube Help does not name 1280 × 720. It recommends 3840 × 2160 and says the image should be as large as possible, because it is also used as the preview image in the embedded player, where a bigger thumbnail stays sharper.
What is the maximum file size for a YouTube thumbnail?
For video thumbnails, YouTube Help gives two limits: 2 MB when you upload from a phone and 50 MB when you upload from a computer. A 3840 × 2160 PNG can easily pass 2 MB, so upload it from a computer or export a smaller JPG for the phone.
Where does the timestamp cover a YouTube thumbnail?
In the bottom-right corner. YouTube Help does not describe the badge, but vidIQ’s thumbnail guide (July 2025) says it is always there. Keep text, faces and logos out of that corner. The badge in the preview is illustrative: its size here is not a YouTube figure.
What size is a YouTube Shorts thumbnail?
YouTube’s English help page says you cannot upload a custom Shorts thumbnail and can only pick a frame. Its en-GB and en-IN pages say you can upload one in YouTube Studio on a computer if your account is verified, with 9:16 recommended and 2160 × 3840 pixels given for Shorts. Which you see depends on the rollout, so check Studio.
Is my image uploaded when I use this checker?
No. The image or video opens in your browser and never leaves your device, and the resized copy is made there too. Close the tab and it is gone. Shared links only carry your settings, such as the format and export size, never the file.