YouTube thumbnail tester
Your thumbnail looks great on a big screen, but most people see it on a phone, about as wide as your thumb. The BolCaps thumbnail tester shows it at that real size next to other videos and points out what nobody will be able to read.
Test my thumbnail
How to do it
- Open the thumbnail checker and pick YouTube thumbnail, Shorts or Reels cover, or Instagram post.
- Choose, drop or paste your picture (JPG, PNG or WebP).
- Look at the phone preview and the list of problems.
- Press Fix my thumbnail for one-click fixes, compare before and after, then download.
What it tests
- Text size at phone size (168 pixels wide, like suggested videos).
- Contrast between each word and the background.
- Areas hidden by the video length badge or the Shorts buttons.
- Whether a face is big enough to see.
- Size and shape: 1280×720 and the 2 MB YouTube limit.
Ask the AI designer
For the idea, the emotion and Urdu or Hindi text, press Ask the AI designer. Your picture is sent to the AI for that step only; the other checks stay on your device.
Frequently asked questions
Is the thumbnail tester free?
Yes. Checks and fixes are free; you sign in with a free account to download the fixed picture.
Will a better score get more views?
Not by itself. A clear thumbnail helps people understand and click, but the title and the video matter too.
Does it work for Shorts and Reels covers?
Yes. Pick Shorts / Reels cover to check the 1080×1920 shape and the areas covered by the buttons.
Can it read Urdu text on my thumbnail?
The quick checks read English letters. The AI designer looks at Urdu and Hindi text too.
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