A quick answer
The free thumbnail preview displays your image and optional title in neutral cards. Your file stays locally in the browser. No account or AI is needed. It does not measure CTR or reproduce every YouTube surface.
Your thumbnail in small views
PNG, JPG or WebP: up to 20 MiB per file, 8192 pixels per side and 16 million pixels in total. Your image stays in your browser and is not uploaded.
The title appears beside your image. It is used only for this preview.
Choose an image to see the preview.
Local in your browser
Your image is not uploaded for the preview.
Small views
Check the subject and text with limited space.
Add the title
Read the image and title together.
How to approach it
Choose a file
Open the thumbnail you want to inspect.
Enter a title
Optionally add the planned video title.
Inspect the cards
Look for small lettering and competing elements.
Revise the design
Change your image and check the new file again.
What to inspect in a small view
Can you recognise the subject without zooming? Read the wording briefly, then look closer. Words that need a second look may need revision.
Judge the title and image together. If both repeat the same sentence, you may be missing a useful explanation.
What a preview cannot prove
The cards provide a neutral presentation. Devices, interfaces and viewers may respond differently.
This tool does not create AI images or predict test results. Use a channel experiment to learn from real responses.
Good to know
Is the tool free?
Yes. Preview needs no account. AI creation in the Studio requires a paid plan.
Is my image transmitted?
The file stays in the browser for this local preview.