YouTube Thumbnail Tester & Preview

Test your YouTube thumbnail and title before publishing — preview them on the homepage, search, sidebar, mobile, tablet and TV.

Thumbnail 1

Thumbnail 2
(optional)

Drag and drop up to 9 thumbnails hereor choose thumbnails from your device

Try to use a 16:9 aspect ratio as it's the most used in YouTube players and previews.
Have a resolution of 1280 x 720
Have a minimum width of 640 pixels
Have a maximum size of 50MB (2MB if uploading from the YouTube mobile app)

0/100

Previews mix in both titles; search and critique use the main title — Swap to switch them0/100

Channel page previews your thumbnail on your own channel — sign in and click your profile picture to save your handle for next time

Preview with top related YouTube thumbnails, searched with your video title, or the query if you enter one

AI Thumbnail Studio

Critique, compare, and improve your thumbnails with AI: a 0–100 score with concrete fixes, a head-to-head winner between two, or an improved redesign of your own image. Add a title and description above for sharper judging.

Upload a thumbnail above to get started

No thumbnail yet? Upload your video to YouTube — unlisted is fine — and the AI will design one from your actual footage. Generate from your video →

How to test a YouTube thumbnail before you publish

Upload your candidates. Drop in up to nine images at once. The tester checks each one against YouTube's requirements — 1280×720, 16:9, at least 640 pixels wide — as it loads.
Type the title you plan to publish with. This is the part a generic mockup cannot do: we search YouTube for that title and build the feed from the videos actually ranking for it, so your thumbnail is sitting next to the ones it will compete against rather than a grid of stock placeholders.
Check every surface. The same thumbnail is rendered in search results, on the homepage, in the suggested sidebar, and at mobile, tablet and TV sizes. A design that holds up full-screen routinely falls apart at 168 pixels wide.
Settle it with a score. Send the winner to the AI critique for a 0–100 score and specific fixes, or put your two front-runners through compare for a direct verdict.

What this thumbnail tester checks

Real competitors, not placeholders. The feed is built from live YouTube results for your title, so “does it stand out?” is answered against the row it will really appear in.
Every size a viewer sees. Homepage, search, sidebar, mobile, tablet and TV — plus your own channel page, which pulls your real banner, avatar and Videos grid if you enter your @handle.
Whether the title and thumbnail agree. Two titles can be previewed at once, and the critique scores how well the image delivers the promise the title makes — a mismatch costs clicks even when both halves are good on their own.
How it reads with colour vision deficiency. View the whole feed as viewers with red-, green- or blue-deficient colour vision would, or in greyscale, which is the fastest way to find a design leaning on one contrast that most people cannot see.
That it will upload at all. Aspect ratio, resolution, minimum width and file size are flagged before you get to YouTube, not after it rejects the image.