Skip to content
Try for free

Free AI tool

YouTube thumbnail rater

Paste a video link. The thumbnail is measured, then graded at the size YouTube shows it on a phone, by the same judge our generator grades its own images with. You get a score out of 5, what holds it back and the fix for each point.

Public or unlisted videos. The thumbnail and title are read from YouTube; nothing is uploaded from your device.

What the rater looks at

The panels show how a result is laid out. The grades and fixes you get depend on your thumbnail.

  1. YouTube video link

    youtube.com/watch?v=...
    AI-generated thumbnail: a reviewer holds black over-ear headphones up to the camera and points at them, eyebrows raised in doubt, with the words WORTH IT?

    01

    The link

    Any public or unlisted video

    Yours or a competitor's. The tool reads the thumbnail YouTube serves and the video's title. Nothing is uploaded from your device.

  2. AI-generated thumbnail: a reviewer holds black over-ear headphones up to the camera and points at them, eyebrows raised in doubt, with the words WORTH IT?
    • Size
    • Duration badge corner
    • Contrast

    02

    The measurements

    What can be measured, is

    The size tells a custom upload from a frame YouTube picked. The bottom-right corner, where the duration badge sits, is checked for detail it would cover. Contrast is measured on the pixels.

  3. Graded 1 to 5 at feed size

    • Focal point
    • Text readable
    • Contrast
    • Emotion
    • Simplicity
    • Keeps the title's promise

    03

    The grades

    Six criteria, judged at feed size

    Focal point, text readable at feed size, contrast, emotion, simplicity, and whether the image keeps the title's promise. Each from 1 to 5, at the size a viewer actually sees.

  4. 1The headline is too small to read at feed size.Fix: Three words, twice the size, high on the frame.

    04

    The fixes

    Up to three, in order of impact

    Each one says what a viewer sees and what to change. Then the generator can write three new angles that fix them, ready for YouTube's A/B test.

What a score can't tell you

No tool can predict your click-through rate from an image, and one that prints a CTR percentage is guessing. CTR depends on who sees the video, where, and next to what.

What can be judged is whether the thumbnail does what clicked thumbnails do: one subject, readable at small size, contrast against the background, a reason to care, and a match with the title. That's what this rater grades, and the same image gets the same grades each time.

The real test is YouTube's own. A/B Testing in YouTube Studio runs up to three thumbnails on the same video and picks the one with the most watch time. Use the rater to decide which three deserve the test.

Want to see a file in a mock feed, without uploading anything? Use the thumbnail tester.

Why a high CTR can be a bad sign: clickbait thumbnails.

When to rate one

  • AI-generated thumbnail: an extreme close-up of a young gamer in a black headset, jaw dropped, lit violet and orange by a Minecraft cave of glowing diamond ore, with the words RAREST DIAMOND

    Before you publish

    Upload unlisted, then rate

    Put the video up as unlisted with your thumbnail, paste the link, fix what it finds, then publish.

  • AI-generated thumbnail: a split frame of the same man, slumped and pale in a dim garage on the left, lean and grinning in a bright home gym on the right, with the words 90 DAYS

    Old videos

    The easiest wins

    A video still on a frame YouTube picked is flagged by its size alone. Those are the first to replace.

  • AI-generated thumbnail: a creator in a hoodie tears open a giant cardboard box covered in painted question marks, mouth open in shock, with the words WORLD'S BIGGEST

    Your niche

    Rate the video that beat yours

    Paste the top video on your topic and see which criteria it wins on.

  • AI-generated thumbnail: a split frame, a tired creator at a cramped desk with an old monitor on the left, the same creator grinning at a bright three-monitor setup on the right, with the words $200 vs $5,000

    Before an A/B test

    Pick the three to test

    Grade your candidates and send the strongest to YouTube's A/B Testing.

Questions, answered

How do I rate my YouTube thumbnail?

Paste the video's link and press Rate it. The thumbnail YouTube serves is measured, then graded at feed size on six criteria from 1 to 5, with up to three fixes. It takes a few seconds.

Can it predict my click-through rate?

No, and be wary of a tool that says it can. CTR depends on the audience, the traffic source and the videos around yours. The rater grades what an image can show: focus, readability, contrast, emotion, clutter and the match with the title.

Can I rate a thumbnail before uploading the video?

This tool reads thumbnails from YouTube links. Upload the video as unlisted with your thumbnail, rate it, then publish. To see an image file in a mock feed without uploading it anywhere, use the thumbnail tester.

What does “automatic frame” mean?

YouTube keeps a 1280 × 720 version only when a custom thumbnail was uploaded. When the largest version is smaller, the image is usually a frame YouTube picked from the video, which is the easiest kind of thumbnail to improve.

Who grades the thumbnail?

The same judge that grades every image our generator makes before you see it, on the same scale. So when you make a new version, its grade compares directly with the one you got here.

Is the thumbnail rater free?

Yes, with no account. Five ratings an hour per visitor, because each one is a call to an AI vision model that costs us money.

Now the thumbnail

Paste the video link. The generator writes the brief from your title, makes the thumbnail and checks it at feed size. Previews are free.

Preview it free