YouTube Thumbnail
Preview
Test your thumbnail and title where viewers will actually meet them: the home feed, search results, the Up next sidebar and the mobile app, in light and dark mode. Drop in competitor videos to see whether yours stands out next to theirs.
1Your thumbnail
Upload or drop your thumbnail
1280×720 JPG or PNG. It never leaves your browser.
2Video details
3Competitor videos
Paste links of videos you compete with (one per line). Their real thumbnails and titles fill the slots around yours.
Your full title fits in home feed.
An approximation of YouTube's layout at a 1280 px desktop window and a 390 px phone. Real layouts vary by screen size and app version.
Thumbnail checks
Upload your thumbnail to check its size, aspect ratio, file size and the timestamp corner against YouTube's requirements.
Small-size readability
Most clicks come from small thumbnails. If you cannot read it at 168 px (the “Up next” size) or 120 px, neither can viewers.
168 px
120 px
How to preview a YouTube thumbnail
Catch the problems before your video goes live, not after the first hour of views.
1. Add your thumbnail
Upload the image from your editor, or paste a link to a video that is already live. Then type the title, channel name and length.
2. Bring in the competition
Paste links to videos ranking for your topic. Their real thumbnails and titles fill the other slots, and Shuffle position moves yours around.
3. Check every surface
Flip between home, search, sidebar and mobile, switch to dark mode, fix what the checks flag, then download a PNG to share with your team.
YouTube thumbnail requirements
YouTube Studio rejects a custom thumbnail that breaks the file rules, and a thumbnail that only just passes can still look soft or get cropped. The preview checks your upload against these numbers automatically.
| Requirement | Value | Notes |
|---|---|---|
| Resolution | 1280×720 px | Minimum width 640 px. Bigger files are scaled down. |
| Aspect ratio | 16:9 | Other shapes get black bars or are cropped in the feed. |
| File size | Under 2 MB | A 1280×720 JPG at 85–90% quality is usually 150–500 KB. |
| Format | JPG, PNG or GIF | Convert WebP, HEIC or AVIF files before uploading. |
| Custom thumbnails | Verified accounts | Phone verification unlocks custom thumbnails in YouTube Studio. |
What this tool helps you with
The questions a designer asks before hitting publish, answered on one screen.
Four Real Surfaces
Home grid, search results, Up next sidebar and mobile feed, drawn at the sizes YouTube uses, so titles wrap where they really will.
Side by Side With Rivals
Load up to eight competitor videos by link and see whether your thumbnail gets lost among theirs.
Light and Dark Mode
Dark backgrounds swallow dark thumbnails. One click shows you how yours reads on both.
Upload Checks
Resolution, 16:9, the 2 MB limit, format, the timestamp corner and a 120 px readability test, with a plain-English fix for each.
Frequently Asked Questions
Common questions about testing YouTube thumbnails.
How can I see how my thumbnail looks on YouTube before uploading?
Upload the image here, type your title and channel name, and switch between the home, search, Up next and mobile views. Nothing is published and the image never leaves your browser.
Why does my title get cut off?
YouTube shows at most two lines of title in the feed, search and sidebar. In the narrow Up next sidebar that is often only 40 to 50 characters. The preview tells you when your title is cut off in the view you are looking at.
What is the timestamp warning?
YouTube puts the video length in a dark box in the bottom-right corner of every thumbnail. The tool looks for text or fine detail in that corner, and you can turn on the timestamp area outline to see exactly what gets covered.
How do the competitor slots work?
Paste links to other videos and the tool loads their public thumbnails and titles from YouTube. Their view counts, upload dates and lengths are placeholders, because YouTube does not publish those without an API key.
Can I test two versions of my thumbnail?
Yes. Download a PNG of the first version, upload the second and download again, then compare the two images side by side. To run a live A/B test on real viewers, use Test & Compare in YouTube Studio.
Does the preview work for Shorts?
This preview covers the 16:9 thumbnails used for long videos in feeds and search. For vertical Shorts, use the YouTube Shorts Safe Zone Checker to see what the Shorts interface covers.
Is this YouTube thumbnail tester free?
Yes. It is free, needs no account, and works on desktop and mobile.
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