Thumbo Lens - Thumbnail Preview & Tester for YouTube

Preview your thumbnail and title among real YouTube videos, compare up to 3 versions, and check text size before you publish. Free.

See your thumbnail where it actually competes: in real YouTube search results, next to the videos you are up against, before you publish. Thumbo Lens opens in Chrome's side panel and stays open while you use YouTube. It also adds a small "Steal style" button when you hover a thumbnail on YouTube (you can switch it off in the panel). HOW IT WORKS 1. Drop, paste or pick your thumbnail. Add up to 3 versions (A, B, C). 2. Type your title and what viewers would search for. 3. Click "Show me in search results". Lens opens that search and puts your thumbnail, title and channel name at result #1, #2 or #3, outlined so you can spot it. 4. Click A, B or C in the panel. The result changes instantly, in the same spot, next to the same competition. CHECKS, IN PLAIN WORDS - Real sizes: your thumbnail at the exact pixel size of a phone feed, desktop Home and the "next video" sidebar, in dark and light mode. - Text size: Lens reads the text on your thumbnail and flags each line that is too small to read on a phone. - Word count: too many words to take in while scrolling. - Timestamp: text hidden under the video length badge. - Blends in: compares your colours with the videos around yours on the page. - Format: 16:9, resolution, and the 2 MB limit for uploads from a phone. ALSO - Works on search results, Home and Subscriptions. Never touches YouTube Studio. - Stop puts the page back exactly as it was. - "Steal style": hover any thumbnail and start a new one in Thumbo from that look. PRIVATE BY DESIGN Nothing you add is sent to Thumbo: your images, titles and settings stay in your browser, the preview changes YouTube only on your screen, and every check runs on your device. The search itself runs on YouTube like any search you type. No account, no ads, no analytics. Free. Made by Thumbo.