A thumbnail is the most-clicked image on the platform, and uploading it at the wrong size means soft edges in search or an awkward crop in the grid. This tool returns the exact dimensions, aspect ratio, format, and file-size limit for every YouTube thumbnail and preview image you might need.
How it works
YouTube’s recommended custom thumbnail is 1280 by 720 pixels in 16:9, with a hard minimum width of 640 pixels and a 2 MB file cap. Because the same image is shown from a tiny search-result tile up to a full-screen preview, designing at the full 1280 by 720 keeps it crisp at every size.
Other content types follow different rules. Shorts take a vertical 9:16 frame from the video as the cover, and the channel grid crops a centre square from it. In-feed ad previews reuse the 16:9 thumbnail but display it small beside copy, so text must be large. Community post images sit best as a 1:1 square. The tool maps each content type to its native spec.
Tips and notes
- Export as a high-quality JPG to stay comfortably under 2 MB while keeping text edges sharp; reserve PNG for thumbnails with flat graphics or transparency.
- Keep critical text and faces inside the central two-thirds — the timestamp badge sits in the lower-right corner of every video tile.
- For Shorts, frame the key subject in the centre so the grid’s square crop does not cut it off.
- Never upload below 640 pixels wide; YouTube will warn you and the preview will look soft on large screens.