YouTube thumbnail preview β does it still read when it shrinks?
You design a thumbnail at 1280Γ720. Nobody watches at that size. In search results it is the size of a postage stamp, and on a phone the title is cut off after two lines. This puts the design where it will actually appear.
The thumbnail and the title are made separately and seen together. When the title is truncated, whatever is written on the thumbnail becomes the only remaining information; when the thumbnail text is illegible, only the title is left. You cannot judge either without the other beside it.
Four placements are shown: desktop home, desktop search, mobile home, and Shorts. Each gives the thumbnail a different size and the title a different amount of room. Light and dark themes both matter β a dark thumbnail on a dark page loses its edges.
Where the title gets cut
Roughly 60 characters on desktop and 40 on mobile. This tool counts against both at once and flags whichever you have passed.
Non-Latin scripts lose out here. The count is in characters, so a Korean or Japanese character counts as one, but it occupies close to twice the width β which means the title can be cut before the number says it should be. Treat the number as a guide and trust the preview.
Put the words that matter at the front. What gets cut is always the end.
What each placement gives you
| Placement | Thumbnail size | Title |
|---|---|---|
| Desktop home | medium, about 360px | two lines, ~60 characters |
| Desktop search | small | one line plus part of the description |
| Mobile home | full screen width | two lines, ~40 characters |
| Shorts | vertical 9:16 | title overlaid on the video |
Shrinking it is the whole test
The usual mistake is judging a thumbnail only at full size. Text that reads comfortably in the editor turns to mush in a search result.
Keep to three or four words, and set them larger than a tenth of the image height β about 70 pixels at 1280Γ720. If the text and the background are close in brightness, that is what disappears first as it shrinks; a contrast checker will tell you the ratio.
A face draws the eye, but at small sizes the expression vanishes. If you are using one, use it large.
Worth checking
- β’Switch to the dark theme. A large share of viewers use it.
- β’The duration badge sits in the bottom-right corner. Text there is covered.
- β’Partly-watched videos get a red progress bar along the bottom. Avoid that strip too.
- β’Compare two thumbnails side by side and see which one your eye reaches first.
- β’Also check it beside your channel's other thumbnails. If they all look alike, none of them stands out.
Frequently asked questions
What are the thumbnail requirements?
1280Γ720 (16:9) is recommended, with a minimum width of 640 pixels. The file must be under 2MB, as JPG, PNG, GIF or WEBP. Anything larger is scaled down by YouTube.
Do Shorts use the same thumbnail?
No. Shorts are vertical 9:16, and without a chosen thumbnail a frame from the video is used. A landscape thumbnail is cropped top and bottom.
Is the preview pixel-accurate?
It reproduces the layout and proportions, not the exact rendering. Real placement varies with window size and with YouTube's own experiments. It is for judging whether the design survives being small.
Is my image uploaded?
No. Everything runs in your browser and nothing is sent anywhere.