The Facebook Thumbnail Size Tool gives you the exact preview-image dimensions Facebook expects for every content surface. Uploading a thumbnail at the wrong size forces Facebook to crop or re-compress it, which produces soft, off-center previews that hurt click-through.
How it works
Each Facebook surface has an officially recommended resolution and aspect ratio. The tool maps the surface you pick to its target pixels (for example 1280 x 720 at 16:9 for landscape video thumbnails, or 1200 x 630 at 1.91:1 for link previews), and lists the accepted file formats plus the maximum upload size. Designing on a canvas that matches those numbers means Facebook displays your image as-is with no automatic cropping.
Tips and notes
For vertical formats (reels and stories at 1080 x 1920, 9:16), keep titles and faces in the central safe zone because the top and bottom strips are covered by interface chrome. Use PNG when your thumbnail contains overlaid text so the edges stay crisp; use JPG for photographic content to keep file size low. Always export at exactly 2x the smallest display size or higher so the image stays sharp on high-density phone screens — but stay under the 8 MB limit to avoid aggressive re-compression.