Thumbnail Readability Tester
Upload your thumbnail and see exactly how it appears at every YouTube display size — from the Home Feed to tiny notification previews.
Drop your thumbnail here or click to upload
JPG, PNG, WebP — see how it looks at every YouTube size
Tips for Readable Thumbnails
Follow these guidelines to make sure your text is legible at every YouTube display size.
Use 3-5 Words Max
Short, punchy text stays readable at every size.
High Contrast Colors
Light text on dark backgrounds (or vice versa) — avoid mid-tones.
Bold, Sans-Serif Fonts
Thin or decorative fonts disappear at small sizes.
Test at Sidebar Size
If it's readable at 168×94 px, it works everywhere.
Need a Better Thumbnail?
Generate optimized thumbnails with AI or preview yours in real YouTube layouts.
Frequently Asked Questions
Why does readability matter for thumbnails?
YouTube displays thumbnails as small as 120×67 pixels in notifications. If viewers can't read your text at that size, they'll scroll past.
What's the smallest size YouTube shows thumbnails?
120×67 pixels in the notification bell. Suggested sidebar shows 168×94 px. Your text should be readable at these tiny sizes.
How many words should a thumbnail have?
3-5 words maximum. Short, bold text performs best because it stays readable even at the smallest YouTube display sizes.
Does this tool upload my image anywhere?
No. Everything runs in your browser. Your image never leaves your device.
What font size works best for thumbnails?
There's no fixed pixel size since it depends on your design. The key test is: can you read it in the Suggested Sidebar preview (168×94 px)? If yes, you're good.