YouTube Thumbnail Preview & Size Checker
Check a thumbnail against YouTube's size rules and see how it reads in the desktop feed, the mobile feed and the suggested-videos rail.
Drop an image here or choose a file
JPG, PNG or WebP · up to 50 MB
The image is decoded locally in your browser. Nothing is uploaded to this site.
Related tools
Crop or fit any image to 16:9, choose the output size and format, then download it locally.
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Related guides
Use the right YouTube thumbnail size, aspect ratio, and available image quality for videos, Shorts, live streams, blogs, and social previews.
7 min read ThumbnailWhy YouTube Thumbnail Quality Options Are Sometimes MissingSee why max resolution thumbnails are not always available, what changes with Shorts and live streams, and how to interpret missing sizes correctly.
7 min readFrequently asked questions
It checks an image against YouTube's published thumbnail specs and shows you how it will look in the three layouts where it competes for a click: the desktop feed, the mobile feed and the suggested-videos rail.
YouTube recommends 3840×2160 at a 16:9 aspect ratio, with a minimum width of 640 pixels. The file must be under 2 MB to upload from a mobile device, and under 50 MB from desktop.
Yes. 1280×720 has the correct 16:9 ratio and comfortably exceeds the minimum width, so YouTube accepts it. It is simply below the current recommended 3840×2160, so the checker flags it for review rather than as a failure.
No. The file is decoded and measured locally in your browser. Nothing is sent to this site's servers, which is why the tool works even with the API offline.
JPG, PNG and WebP — the same three formats YouTube accepts.
No, and any tool that claims to is guessing. This checker reports fixable, factual problems — wrong ratio, too small, too large a file, unsupported format — and lets you judge the design yourself in the real layouts.
The suggested-videos rail renders thumbnails at roughly a quarter of the desktop feed's width. Text that is comfortable at 1280 pixels wide is often unreadable there, which is exactly why previewing all three contexts is worth the thirty seconds.
Only partly. Shorts are vertical and YouTube picks their cover frame differently, so a 16:9 check does not apply. Use this tool for regular videos and live streams.
They are two halves of one job: the preview tool tells you what is wrong, and the resizer fixes it. Each links to the other, so you can loop until every check passes.