PSB, also called Photoshop Big or Photoshop Large Document Format, is a proprietary image file format used by Adobe Photoshop. PSB files have the extension .psb, and can store a maximum image size of 300,000 pixels in each dimension. By comparison, the maximum size of an image saved in PSD (Photoshop Document) format is 30,000 pixels per dimension, which is 100x smaller than PSB (10x smaller per dimension).

Like PSD, the PSB format supports image layers, and 32 bpc (bits per channel) color, also known as HDR (high dynamic range).

Color depth, Photoshop terms, Software terms

  • What’s the difference between 16-bit, 24-bit, and 32-bit color?
  • What file types can a picture be saved as?
  • File extensions - P