YouTube Thumbnail Reader & Preview
Simulate how your thumbnail text and titles render on desktop, sidebar, and mobile layout screens before uploading.
Test how your thumbnail image and title layout look in simulated YouTube feeds privately
This is how your video title will look in the YouTube algorithm home feed!
This is how your video title will look in the YouTube algorithm home feed!
How to use this tool
Thumbnail Accessibility
Over 70% of YouTube users watch on mobile devices. Thumbnail text that looks readable on a large monitor during design is often completely illegible on small mobile screens.
How to Preview Your Designs
Upload a mockup layout to test title truncation and copy legibility across devices.
Upload Image File
Select your thumbnail image mockup from your local files (kept entirely private in your browser).
Type Video Title
Input your target video title to verify where characters truncate.
Inspect Layouts
Check how the design displays in home feeds, sidebars, and mobile columns.
Frequently Asked Questions
Thumbnail optimization principles.
What is the ideal thumbnail size?
The standard size is 1280 x 720 pixels (16:9 aspect ratio) with a minimum width of 640 pixels, saved in JPG, PNG, or WebP formats, under a 2MB file size limit.
At what character length does YouTube truncate titles?
YouTube typically truncates titles around 60 to 70 characters depending on letter widths. Keeping your main hooks in the first 50 characters ensures they remain visible.
Privacy & Safety Policy
All tools run completely in your browser via client-side JavaScript. We do not upload your files, interest parameters, or JSON payloads to any server. Your data remains yours.