When you attempt an action in Adobe Photoshop, you might encounter an error message stating, “Could not complete your request because the scratch disk is full.”

To prevent the scratch disk full error, adjust how Photoshop utilizes your computer’s memory.

How to Fix the Photoshop Scratch Disk Full Error

Follow these steps in order to troubleshoot the scratch disk full error in Photoshop:

1. Free up disk space. Clear some space on the Mac or Windows drive that is defined as the scratch disk in Photoshop Preferences. For best results, use a free disk space analyzer tool like Disk Cleanup.

2. Delete Photoshop temporary files. You can safely delete temporary files associated with Photoshop to free up scratch disk space. Photoshop temp files are typically named ~PST####.tmp on Windows and Temp#### on Mac (where #### is a series of numbers).

3. Defragment the hard disk. It’s possible to get the scratch disk is full error when the scratch disk drive has free space. This is because Photoshop requires contiguous, unfragmented free space on the scratch disk drive. If you get the error message when the scratch disk drive shows a good amount of free space, run a disk defragmentation utility.

4. Clear the Photoshop cache. If you can open Photoshop, delete temporary files by navigating to Edit > Purge > All (on Windows) or Photoshop CC > Purge > All (on Mac).

   Purging the cache prevents you from undoing recent changes you made to images.

5. Clear Crop tool values. If you encounter the error when cropping an image in Photoshop, it might result from incorrect unit values in the options bar for the Crop tool. For instance, entering dimensions of 1200×1600 with units set to inches rather than pixels results in a large file that could trigger the scratch disk full message. To prevent this problem, select Clear in the options bar after you select the Crop tool.

6. Change the Photoshop performance settings. Go to Edit > Preferences > Performance (on Windows) or Photoshop CC > Preferences > Performance (on Mac), then adjust the sliders under Memory Usage to increase the amount of RAM that Photoshop is allowed to utilize.

   Setting the memory usage above 80% can cause the computer to run slow.

7. Change or add additional scratch disks. If possible, create a new hard drive partition for the Photoshop scratch disk. Although Photoshop functions with a single scratch disk on the system partition, you can improve performance by setting the scratch disk to be the fastest drive in your system.

   To change the scratch disk location and establish additional scratch disks from Photoshop Preferences:

   • On Windows, select Edit > Preferences > Scratch Disks, or press Ctrl+Alt.
   • On macOS, select Photoshop CC > Preferences > Scratch Disks, or press Command+Option.

What Causes the Photoshop Scratch Disk Is Full Error?

The Photoshop scratch disk refers to your hard drive. Photoshop uses the hard drive as temporary swap space, or virtual memory, when your system doesn’t have enough RAM to perform an operation. If you only have one hard drive or partition in your computer, the scratch disk is the drive where the operating system is installed (for example, the C: drive on a Windows system).

When that drive runs out of space, it prevents Photoshop from working properly. For example, if Photoshop crashes in the middle of an editing session, this improper shutdown may leave large temporary files on the scratch disk. Consequently, Photoshop may fail to reopen, necessitating troubleshooting on the hard drive.