6 items
Open ThumbView to compare multiple thumbnail variants across grid, list, mobile, and size previews. ThumbView Previewer helps creators test YouTube thumbnails before publishing. Upload, paste, or load a thumbnail from a YouTube URL, then preview it inside realistic YouTube-style layouts. See how your thumbnail looks in the home feed, search results, suggested sidebar, mobile feed, and real display sizes. Key features: Preview thumbnails in a YouTube-style feed with real surrounding thumbnail images. Test PC, tablet, and mobile layouts. Switch between light mode and dark mode. Check home feed, search results, suggested sidebar, mobile feed, and size preview views. Upload, drag and drop, paste, or load a public YouTube thumbnail from a video URL. Edit title, channel name, duration, views, and upload age. Shuffle placement to compare your thumbnail against neighboring videos. Use stress tests like squint, monochrome, dim, and tiny view. Review basic thumbnail readiness checks for aspect ratio, resolution, contrast, brightness, and title length. Optionally inject your preview thumbnail into the current YouTube tab for temporary local testing. ThumbView Previewer stores your thumbnail and preview settings locally in Chrome storage. The extension does not require an account and does not collect personal data.
May 25, 2026
rating_count is the Chrome Web Store ratings count, not a written-review count.
Media assets
Screenshots and videos on the listing.
Has promo video
Whether the listing includes at least one video.
Languages
Declared language locales.
Developer website
Listing exposes a developer website URL.
Contact email
Listing exposes a contact email.
Keyword in name
Case-insensitive substring match in the name.
Keyword in description
Case-insensitive substring match in the description.
Keyword occurrences in description
Count of case-insensitive occurrences in the description.
Category user-count percentile
Share of same-category extensions with fewer users (null if unknown).
These are transparent listing completeness / keyword signals, not a prediction of Chrome Web Store search ranking.