Add bold and italic text, count characters, and preview the "…see more" cut.
- Runs in your browser
Social content
YouTube thumbnail preview
A thumbnail can look great in your design tool and still get lost in a busy feed, and a long title gets cut off. See yours on YouTube's home page, in search, beside a playing video, and on a phone, in light and dark. Compare up to three thumbnails. Your images never leave your device.
- Free
- No sign-up
- Runs in your browser
Three steps
How it works
Add your thumbnail, or up to three to compare. Or try the sample.
Type your title, channel name, views, upload age, and video length.
Switch layouts and themes to see how each thumbnail stands out and where the title gets cut.
GuideReviewed
How to check a YouTube thumbnail and title before you publish
Contents
YouTube's thumbnail requirements
These come from YouTube's help page on custom thumbnails, checked in October 2026. The file size limits are firm and YouTube asks for a minimum width; the size, shape, and format are its recommendations.
- Size: 3840 × 2160 pixels, and at least 640 pixels wide.
- Shape: 16:9 for regular videos. Shorts thumbnails are 9:16, at 2160 × 3840.
- Format: JPG or PNG.
- File size: up to 2 MB from the YouTube app on a phone, or 50 MB from a computer.
- Account: custom thumbnails need a verified YouTube account.
Why your title gets cut
YouTube allows titles of up to 100 characters, but most layouts show only part of that. On the desktop home page and in search, a title gets two lines; beside a playing video, three; on a phone, two. Anything longer ends in an ellipsis.
The preview wraps your title at the sizes YouTube used on October 18, 2026, and lists the words each layout hides. Treat the breaks as close estimates: screen sizes, fonts, and YouTube's own design tests move them a little.
Make the thumbnail readable at every size
In a 1440-pixel-wide browser window, the same image shows about 347 pixels wide on the home page, 500 in search, and 218 beside a playing video. Big shapes, a few large words, and strong contrast survive the smallest size; fine detail and small text don't.
YouTube shows the video length in the bottom-right corner of the thumbnail, so keep faces, logos, and words away from it. Check the dark theme too: a thumbnail with dark edges can blend into a dark page.
Compare thumbnails before you publish
Add up to three thumbnails to see them side by side in every layout, labeled A, B, and C, each with its own checks. Pick the one that reads fastest at the smallest size.
Once the video is live, YouTube Studio on a computer can test up to three titles and thumbnails with real viewers and keep the one with the most watch time.
Frequently asked
Questions, answered.
What people ask before they use the YouTube thumbnail preview.
No. The preview runs entirely in your browser. Your images are opened and shown on your device and never sent to a server.
YouTube recommends 3840 × 2160 pixels in a 16:9 shape, at least 640 pixels wide, saved as a JPG or PNG. Keep it under 2 MB if you upload from the YouTube app on a phone; from a computer, YouTube accepts files up to 50 MB.
Up to 100 characters, without < or >. Far fewer show in most places: the home page and search give a title two lines, so the end of a long title is cut. The preview shows exactly where.
The thumbnail and title sizes were measured on YouTube on October 18, 2026, in a 1440-pixel-wide window and on a phone. YouTube changes its layout and tests new designs, and fonts differ between devices, so line breaks are close estimates, not guarantees.
Yes. Add up to three. They show side by side in every layout, labeled A, B, and C, and choosing one shows its checks.
No. The layouts are for regular videos, which use 16:9 thumbnails. YouTube recommends 2160 × 3840 (9:16) for Shorts thumbnails, and the checks point it out if you add a 9:16 image here.
No. It's an independent free tool. The layouts are inspired by YouTube's and use its sizes, without YouTube's logo or branding.
More free tools
All free toolsWrite your slides, pick a template and colors, and download a PDF for LinkedIn.
- Runs in your browser
Check one draft against every platform's limit, counted the way each platform counts.
- Runs in your browser
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From Ampere
Thumbnail checked. Now make the next one.
Ampere is an AI marketing agent that creates YouTube thumbnails, scripts, hooks, and captions from your saved Brand memory, ready for your review.
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