Home : File Types : PSD File

.PSD File Extension

File TypeAdobe Photoshop Document

DeveloperAdobe Systems
4.2 (611 Votes)
CategoryRaster Image Files

What is a PSD file?

A PSD file is an image file created by Adobe Photoshop, a professional image-editing program often used to enhance digital photos and create web graphics. It is the native format used to save files in Photoshop. PSD files may include image layers, adjustment layers, layer masks, annotations, file information, keywords, and other Photoshop-specific elements. They are commonly created and shared among graphics professionals.

More Information
Screenshot of a .psd file in Adobe Photoshop 2020
PSD file open in Adobe Photoshop 2020

You can modify PSD layers and other elements such as images, shapes, text, and effects. The PSD format supports RGB, CMYK, grayscale, monochrome, duotone, indexed color, Lab color, and multichannel color modes.  The color mode can be changed within the Image → Mode submenu. When you are ready to publish the image, you can export it to standard image formats such as .JPEG, .GIF, and .PNG.

While PSD files are saved in a proprietary format, they can be opened directly with Apple Preview, which is included with macOS.  They can also be opened by media programs included with Windows if the correct codec, such as the Ardfry PSD codec, is installed.  Examples include Windows Explorer, Windows Photo Viewer, and Windows Media Center.

What is the data structure of a PSD file?

The Photoshop file format is separated into five major parts:

  1. File Header - contains the basic properties of the image such as the version, number of channels in the image, number of bits per channel, pixel height and width of the image, and the color mode of the file (bitmap, grayscale, RGB, CMYK, Multichannel, indexed, duotone, and lab).
  2. Color Mode Data - specifies the length of the color data, which is set to 0 unless the color mode is indexed or duotone as specified in the file header.  If this is the case, the color data for indexed color and duotone images is also stored in this section.
  3. Image Resources - specifies the length of the image resource section and the image resources, which is a series of blocks each with a resource ID that indicates the type of data stored in the block.  These blocks are used to store non-pixel data associated with the image, such as pen or pencil tool paths.
  4. Layer and Mask Information - contains information about layers and masks, which includes the number of layers, channels in the layers, blending ranges, adjustment layer keys, effects layers, and mask parameters.
  5. Image Data - contains the actual image data and the data compression method and the image pixel data.  Different compression methods may be raw image data, RLE compression, Zip without prediction, or Zip with prediction.
Open and view .PSD files with File Viewer Plus.

Programs that open PSD files

Updated 11/7/2019

About PSD Files

Our goal is to help you understand what a file with a *.psd suffix is and how to open it.

The Adobe Photoshop Document file type, file format description, and Mac, Windows, Linux, Android, and iOS programs listed on this page have been individually researched and verified by the FileInfo team. We strive for 100% accuracy and only publish information about file formats that we have tested and validated.

If you would like to suggest any additions or updates to this page, please let us know.