Thumbnail Size Checker
Get the exact recommended thumbnail and cover image dimensions, file size limits, aspect ratios, and supported formats for every major platform.
Platform Image Spec Checker
All Platform Quick Reference
| Platform | Type | Dimensions | Max Size | Ratio |
|---|
Why Thumbnail Dimensions Matter
Uploading an image at the wrong size causes platforms to crop, stretch, or compress your thumbnail — leading to blurry visuals and cut-off text. Each platform has specific recommended dimensions optimised for its display grid, mobile rendering, and compression algorithm. Using the correct size from the start protects image quality across all devices.
YouTube Thumbnails
YouTube's ideal thumbnail size is 1280×720 pixels at a 16:9 aspect ratio. This matches HD video format and displays sharply across desktop, mobile, and TV interfaces. The maximum file size is 2MB. JPG is the most widely used format for thumbnails due to its compression efficiency, though PNG is better for text-heavy designs.
Vertical Formats for TikTok and Instagram Stories
Short-form vertical video platforms use 9:16 portrait orientation — the natural smartphone screen ratio. TikTok cover images and Instagram Stories/Reels should be 1080×1920 pixels. Keep key elements within the centre safe zone to avoid cropping from platform UI elements at the top and bottom of the frame.
Tips for Click-Worthy Thumbnails
High contrast colours stand out in feeds. Human faces showing emotion drive higher click-through rates. Keep text to 3–5 words maximum, use a font size readable at 120×90px (the smallest grid thumbnail size). Leave breathing room around the edges for safe cropping, and always export at 72–96 DPI for screen use.