How it works
- Open the extension and upload your thumbnail, title, channel name and length.
- Refresh YouTube. Your card appears at a random spot on the home page and in search.
- Find it the way a viewer would. If it’s hard to spot, it needs more contrast or a clearer title.
Works only in your browser. No account, nothing uploaded, other people don’t see your test card.
Install
The Chrome Web Store listing is on its way. You can install the test build now:
- Download and unzip the file.
- Open chrome://extensions and turn on Developer mode.
- Click “Load unpacked” and pick the unzipped folder.
Next stepThumbnail & title previewSee your video in a real-looking feed
Want packaging that earns the click? Titles and thumbnails are part of every edit I deliver.
Start a videoHow to use the thumbnail Check extension
- Install the extensionChrome, Edge, Brave and other Chromium browsers.
- Add your thumbnailUpload it in the extension popup with your title.
- Look for it on YouTubeJudge it among the real videos in your feed.
Questions
Does anyone else see my test thumbnail?
No. It only appears in your own browser.
Does it need my YouTube account?
No login and no permissions to your channel.
Which browsers work?
Chrome and other Chromium browsers such as Edge and Brave.
Is there a version without installing?
Yes, the online thumbnail preview tool.