How much space does Photoshop use on the scratch disk?

Photoshop can use anywhere from 2GB to 200GB of scratch disk space depending on the file size and complexity. For large multi-layer compositions, 50GB of free space is a safe minimum.

How to Clear Scratch Disk in Photoshop (Free Web Guide)

The 'Scratch disks are full' error is arguably the most frustrating notification in Photoshop. It happens when Photoshop runs out of memory and hard drive space to store temporary project files. We’ll show you how to fix this, and introduce you to a modern editor that never eats your hard drive space.

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Why Does the Scratch Disk Error Happen?

Photoshop is a heavy desktop application. When working on large files, it writes massive temporary cache files to your hard drive (the scratch disk). If your C: drive only has a few gigabytes of free space left, Photoshop will completely freeze and lock you out from saving your work until you free up space.

How to Clear It in Photoshop

Follow these exact steps to execute the operation flawlessly.

Purge Cache

Open Photoshop. Go to Edit > Purge > All. This deletes the clipboard and history cache. Note: You cannot undo any previous actions after doing this.

Change Scratch Disk Preference

Go to Edit > Preferences > Scratch Disks (Windows) or Photoshop > Preferences > Scratch Disks (Mac). Check the box next to another hard drive that has more free space.

Delete Temp Files Manually

If Photoshop won't even open, you must manually delete files. Go to your local Temp folder (Windows: %temp%) and delete files starting with '~PST' or 'Photoshop Temp'.

The Permanent Fix: Use a WebGPU Editor

What if you didn't have to dedicate 50GB of your hard drive just to edit a photo? PhotoQuill is 100% free photo editing software powered by WebGPU. It runs entirely inside your browser. Because it doesn't install massive local caches, you will never see a Scratch Disk Full error again. You can open huge PSD files instantly without deleting your personal files.

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Frequently Asked Questions

How do I stop Photoshop from filling my scratch disk?

The best prevention is to set your scratch disk to a secondary drive with plenty of free space (at least 20GB). Go to Edit > Preferences > Scratch Disks and uncheck your C: drive, then check your D: or external drive.

Will clearing the cache delete my work?

No. Purging via Edit > Purge > All only clears the undo history and clipboard. Your current project document is not affected. However, you will no longer be able to undo past actions that were in the cache.

How much space does Photoshop need on the scratch disk?

Photoshop can use anywhere from 2GB to 200GB of scratch disk space depending on file complexity. For large multi-layer compositions, 50GB of free space is a safe minimum.

Is there photo editing software that does not use a scratch disk?

Yes. PhotoQuill is free photo editing software that runs in the browser using your GPU. It does not write large temporary files to your hard drive, so scratch disk errors are impossible.