You can spend days editing the perfect video, but if your thumbnail is blurry or cropped, nobody will watch it. The YouTube Thumbnail is the billboard for your content, and getting the dimensions right is the first step to a high Click-Through Rate (CTR).
Google explicitly recommends 1280×720 pixels as the ideal size. While you technically can upload smaller images, they will look pixelated on high-resolution desktop screens and TV apps.
The Official Specs
- Dimensions: 1280 pixels (width) by 720 pixels (height).
- Minimum Width: 640 pixels.
- Aspect Ratio: 16:9.
- File Size: Under 2MB (This is a strict limit!).
- File Type: JPG, GIF, BMP, or PNG.
The “Time Stamp” Danger Zone
Designing a thumbnail has one major trap: The Time Stamp.
YouTube overlays the video duration (e.g., “10:05”) in the bottom-right corner of every thumbnail.
Critical Tip: Never put anything important in the bottom-right corner. If you put your text or a surprise element there, the black time stamp box will cover it up.
Why 1280×720?
YouTube uses a 16:9 player. If you upload a 4:3 image or a square image, YouTube will add black vertical bars (pillarboxing) to the sides, making your video look amateur before it even starts. Stick to 1280×720 to fill the frame perfectly.