YouTube Thumbnail Size and Free Resizer for 2026

3840 x 2160 is the current answer. In 2022, YouTube's help page asked for 1280 x 720 pixels, JPG, GIF or PNG, and a 2 MB limit, as an archived copy of the page shows. Most size guides still repeat those numbers. The page today recommends 3840 x 2160, has dropped GIF from its examples, and allows 50 MB from a computer.

A 1280 x 720 thumbnail still uploads. It is twice the 640 pixel minimum, so there is no reason to redo an old library for size alone. YouTube says the thumbnail is also the preview image in the embedded player, which is where a bigger file shows its extra detail.

One case where 1280 x 720 is the floor that matters: YouTube's A/B test (more on that below) shrinks every thumbnail in a test to 854 x 480 if any one of them is under 1280 x 720.

The limit depends on where you upload, per YouTube's thumbnail page. From the YouTube app on a phone, it is 2 MB for a video thumbnail and 10 MB for a podcast. From YouTube Studio on a computer, it is 50 MB for everything.

To fit a limit, the tool saves the JPG at 92% quality first. If that is too big, it tries 86%, then 80%, and so on down to 40%, and keeps the first file that fits. Pixel size never changes, so you still get 3840 x 2160. The export is the browser's own canvas toBlob, which is why nothing has to leave your computer.

We ran it on 3 November 2026 in a Chromium browser (Chrome 152). A 4032 x 3024 test picture covered in heavy grain, made to be hard to compress, came out at 2.9 MB as a 3840 x 2160 JPG. With Under 2 MB chosen, the tool stepped down to 80% quality and saved 1.6 MB. The macOS Sonoma wallpaper, a 6016 x 6016 picture with smooth color, came out at 412 KB as a 4K JPG and 10 MB as a 4K PNG. A flat yellow and red design with big words, exported the same way, was 195 KB as PNG. Other browsers encode JPG a little differently, so your numbers will move a few percent.

What that means in practice: photos belong in JPG, and a 4K PNG of a photo will not pass the phone limit at all. The tool tells you when a PNG is over and does not shrink it for you. Flat graphics with sharp text are the case for PNG, and they stay small.

A Shorts thumbnail is 2160 x 3840 pixels at 9:16, at least 640 pixels tall. You can only add one in YouTube Studio on a computer for now, from Content, then the Shorts tab, and the account has to be verified, according to YouTube's thumbnail page.

Upright videos have a trap. If you give one a 16:9 custom thumbnail, YouTube replaces it with an automatic 4:5 thumbnail on the Home, Explore and Subscriptions pages. Your 16:9 picture still shows in the watch feed, in watch history and outside the mobile apps. For an upright video, make the thumbnail upright too: pick Shorts 2160 x 3840 in the resizer.

YouTube's own A/B test does not work for Shorts, so you cannot compare Shorts thumbnails inside Studio.

Videos use 16:9, the shape of the player. 3840 x 2160, 1920 x 1080 and 1280 x 720 are all 16:9, so any of them fills the frame. The tool tells you when your picture is a different shape before you download.

Phone photos are usually 4:3 or upright, so something has to give. Fill and Crop cuts off the top and bottom; drag until the face and the words sit where you want them. Fit Whole Picture keeps everything and puts a blurred copy behind it, which works for a screenshot or a book cover you must not crop. Never stretch a picture to 16:9 in another app. People notice a squashed face at once.

YouTube's thumbnail pages give no safe area, unlike its rules for channel banners. Look at any list of videos, though, and two things sit on top of the picture. The length of the video is a small dark label in the bottom right corner. And on a video someone has partly watched, a red progress bar runs along the bottom edge.

So keep the bottom right corner free of anything important, such as a price, a score or the last word of your text. Put the face and the words in the top two thirds and toward the left. The resizer does not draw these overlays for you, so check the corner yourself in the small copy.

YouTube gives no point size. Its tips page asks for a font that is easy to read, and its thumbnail page shows Ask Studio being told to make the text larger. The practical test is the small copy in the tool. If the words still read in the 120 pixel one, they are big enough for a crowded list on a phone.

Our working limit is three to five words. A heavy font, light text on a dark area or the other way round, and a thin outline or shadow behind the letters all help. If the words only repeat the title, cut them; the title sits right next to the thumbnail.

The usual cause is a small source picture. A frame grabbed from a 720p video, or a screenshot of something on screen, has too few pixels to make 3840 x 2160. The tool says when it has to enlarge your picture and by how much, and the bigger that number, the softer the result. Export the frame from your editing app at full resolution instead.

The second cause is a heavy squeeze to get under 2 MB. If the tool had to drop JPG quality a long way, upload from a computer instead, where the limit is 50 MB and the file can stay at 92%.

The third is the A/B test: if any thumbnail in a test is under 1280 x 720, YouTube's Test & compare page says all of them are shown at 854 x 480. And if you just changed a thumbnail and still see the old or a fuzzy one, wait. YouTube notes that a new thumbnail can take some time to show everywhere.

On a computer, sign in to YouTube Studio, click Content in the left menu, and click the video. Under Thumbnail, click Upload file, pick the file from the resizer, and click Save. For a Short, click the Shorts tab in Content first, then do the same with a 9:16 picture. These are YouTube's steps.

Under Thumbnail there is also Get suggestions, where YouTube makes thumbnails from your video. Ask Studio, in the same publishing flow, reads the video's transcript and themes and makes thumbnails from a prompt such as Create a thumbnail. Both are worth a look before you design one by hand.

YouTube Studio has a built in test called Test & compare. You upload up to 3 thumbnails, 3 titles, or both, and YouTube shows them to different viewers. When the test ends, the version with the most watch time goes to everyone. It is judged on watch time, not clicks, so a thumbnail that draws clicks and loses viewers fast will not win. These details are on YouTube's Test & compare help page.

To start one, open the video in Studio and click A/B Testing in the Title box or under Thumbnail, choose what to test, upload your versions and click Done. A test takes from a few days to two weeks. The result reads Winner, Performed Same or Inconclusive; when it is inconclusive, the first thumbnail you uploaded stays.

The limits: computer only, advanced features must be turned on, and it does not run on Shorts, videos made for kids, mature or age restricted videos, private videos, scheduled live streams or Premieres that have not ended yet. Changing the title or thumbnail during a test stops it. Make every version at least 1280 x 720 so none of them gets shrunk to 854 x 480.

The resizer only resizes, crops and compresses. It does not add text, design a thumbnail or upload to YouTube; you upload the file yourself in Studio. Its small copies are a quick check at two widths, not YouTube's real layout, and they leave out the length label in the corner. It saves JPG or PNG only, and if even 40% JPG quality cannot get under the limit, it tells you the file is over instead of shrinking the picture. When you need more than that, these work.

On a Mac, Preview can do it in two steps, following Apple's Preview guide. Crop first: show the Markup toolbar, click Rectangular Selection, drag a box close to 16:9 and click Crop. Then choose Tools, then Adjust Size, turn on Scale proportionally and type 3840 as the width. Getting exactly 2160 tall by hand is fiddly, which is the main reason the resizer exists.

In Canva, Figma or Photoshop, start a 3840 x 2160 canvas. If your template is 1280 x 720, scaling it up by exactly 3 gives 3840 x 2160 with the layout intact. Text and shapes stay sharp; photos inside it only stay sharp if the originals are big enough.

YouTube only reads pixels, so the pixels per inch setting in a design app does not change anything once the file is exported. If the app asks anyway, 3840 x 2160 at 300 pixels per inch is 12.8 x 7.2 inches, or 32.5 x 18.3 centimeters. At 72 pixels per inch the same file is 53.3 x 30 inches.

Your channel banner has its own safe area, and the YouTube banner size resizer draws it on your picture. The profile picture and the video watermark are covered on YouTube's branding help page. For upright pictures on Instagram, the Instagram story size tool makes 9:16 files and marks Meta's safe zone for text. Sizes for every network are in the social media image sizes guide, and title and description limits are in social media character limits.

Spreadcast does not make thumbnails; the resizer above is free and stands on its own. What it does is the posting around each video: it designs posts in your brand, writes a caption for each network and schedules them to YouTube, Instagram, TikTok, LinkedIn, Pinterest, Facebook, Threads, Bluesky, Mastodon, Telegram and Discord from one calendar. If you work in Claude or ChatGPT, the YouTube MCP server lets your assistant draft and schedule those posts.

If you make an app, start free with your App Store link: Spreadcast reads the listing and makes your first posts from it, three on the free plan, before you pay anything. For any other channel or brand, the plans page shows what each plan includes.