YouTube Thumbnail Preview Tester
Upload a thumbnail and fill in your title to see exactly how they'll look in three places viewers actually see them: search results, the suggested-videos sidebar, and the mobile home feed.
Nothing is uploaded anywhere — the image is rendered locally in your browser using JavaScript.
Desktop search result
Suggested videos sidebar
Mobile home feed
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How it works
- 1Upload your thumbnail image (any size — it'll be cropped to YouTube's 16:9 the same way YouTube does).
- 2Type your title and, optionally, your channel name and video length.
- 3Compare the three live mockups below and adjust until it reads well small.
When to use this
- You just finished a thumbnail and want to catch a legibility problem before you publish, not after.
- You're deciding between two thumbnail options and want to see them at real feed size, not full-screen in your editor.
- You want to check that your title and thumbnail aren't both saying the same thing.
A worked example
Upload a thumbnail with bold overlay text and type in a candidate title. The search-results mockup renders at roughly the size YouTube actually shows — around 246×138px on desktop — which is usually the moment text that looked fine at full size turns out to be unreadable. If it holds up shrunk that small, it will hold up in a real feed.
Frequently asked questions
Why does my thumbnail look small on mobile?+
Most watch time on YouTube happens on mobile, where thumbnails render tiny. Titles and thumbnails that only work at full size often fail on a phone — that's exactly what this tool is for.
What size should my thumbnail be?+
YouTube recommends 1280×720px (16:9 ratio), under 2MB, as JPG, GIF, or PNG.
Does this account for the video-length badge overlapping my thumbnail?+
The mockups reflect where YouTube typically places the duration badge in the bottom-right corner — worth checking that your thumbnail's important detail isn't sitting directly under it.
Is my uploaded image sent to your servers?+
No — it's rendered locally using JavaScript in your browser and never leaves your device.
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