Free YouTube Thumbnail Compressor
Thumbnail too big for the YouTube app? Shrink it under the 2 MB phone limit — or any size you choose — at the highest quality that fits, and compare before and after. Free, no sign-up, nothing uploaded.
Size in pixels
Format
JPG is what YouTube accepts (with PNG).
Wrong shape instead of too big? Resize it to 3840×2160 or 1280×720.
How to compress a YouTube thumbnail
Get under the limit without making your thumbnail look worse.
- 1
Drop your thumbnail
JPG, PNG or WebP in any size — a 4K export, a PNG from your design app or a screenshot. It is compressed right in your browser.
- 2
Pick the limit
Under 2 MB is chosen for you, because that is the limit for video thumbnails in the YouTube phone app. Choose 1 MB, 500 KB or your own limit for other uses.
- 3
Compare and download
Drag across the picture to compare the original and the compressed file, zoom in on faces and text, then download the JPG.
Why YouTube says your thumbnail is too big
YouTube applies two file size limits to custom thumbnails. In YouTube Studio on a computer, video, Shorts and podcast thumbnails can be up to 50 MB. From the YouTube phone app, video thumbnails are limited to 2 MB (podcast thumbnails to 10 MB).
The pixel size is rarely the problem — the file format is. A 1280×720 JPG at high quality is usually only a few hundred kilobytes, while a 3840×2160 PNG of a photo is often more than 10 MB. Saving the same image as a well-tuned JPG solves it in almost every case.
If you upload from your phone, a 1920×1080 or 1280×720 JPG under 2 MB looks sharp in every feed. If you upload from a computer, you can keep the full 4K version. See the full rules in the YouTube thumbnail size guide.
Thumbnail compressor FAQ
What is the maximum file size for a YouTube thumbnail?
2 MB for video thumbnails uploaded from the YouTube phone app (10 MB for podcasts) and 50 MB for video, Shorts and podcast thumbnails uploaded in YouTube Studio on a computer.
Why is my thumbnail too big for the YouTube app?
Usually because it is a PNG or a 4K export. A 4K PNG of a photo is often over 10 MB, while the same image as a high-quality JPG is a fraction of that. Compress it to a JPG under 2 MB here, or upload it from a computer, where the limit is 50 MB.
Will compressing make my thumbnail blurry?
Not at sensible sizes. The compressor searches for the highest JPG quality that still fits your limit, so it removes only as much as it must. Only if even a low quality would be too big does it scale the picture down a little, and it tells you when it did.
Should I upload a JPG or a PNG to YouTube?
Both are accepted. JPG is the better choice for photographic thumbnails because it is much smaller at the same visible quality. PNG suits flat graphics but is often too big for the phone app.
Can I use WebP for a YouTube thumbnail?
YouTube's help center lists JPG and PNG for thumbnails, so upload a JPG to YouTube. WebP is a great choice for the same image on your website or blog, where it loads faster.
Is my image uploaded?
No. The image is compressed inside your browser and never sent to ThumbMagic or anyone else.
Skip the file-size struggle next time
ThumbMagic exports every thumbnail in 4K for computer uploads and as a 1280×720 file that always stays under 2 MB for the phone app. Your first thumbnail is free.
More free thumbnail tools
- YouTube Thumbnail TesterPreview your thumbnail in the home feed, on a phone, in search and in the up-next list. Compare up to three options and check size, ratio, file size and contrast.
- YouTube Thumbnail ResizerResize any image to 3840×2160, 1920×1080, 1280×720 under 2 MB, Shorts or social sizes. Drag to choose the crop, or fit it without cropping.
- YouTube Thumbnail Safe Zone CheckerSee where YouTube puts the video length, the progress bar and its buttons over your thumbnail, so your text and faces stay visible.
- YouTube CTR CalculatorWork out your impressions click-through rate and see how many more views a stronger thumbnail would bring from the same impressions.