---
id: mac-storage-basics.why-are-virtual-machines-so-large
url: https://storagestudio.us/faq/mac-storage-basics/why-are-virtual-machines-so-large
category: "Mac storage basics"
subcategory: "Developer tools"
question: "Why do virtual machines take up so much space, and how do I shrink them?"
alt_questions:
  - "parallels vm size mac"
  - "utm disk image large"
  - "vmware fusion space"
  - "shrink virtual machine mac"
  - "vm snapshots taking space"
short_answer: "A VM image contains a whole operating system, and snapshots add copies of changes. Delete unneeded snapshots, use the app's reclaim/compact option, or keep VMs on an external SSD."
tags: ["virtual machines", "parallels", "utm"]
related: ["https://storagestudio.us/faq/mac-storage-basics/how-do-i-exclude-folders-from-time-machine", "https://storagestudio.us/faq/mac-storage-basics/can-i-keep-developer-projects-on-an-external-drive"]
applies_to: "all"
last_reviewed: 2026-10-01
---

# Why do virtual machines take up so much space, and how do I shrink them?

A virtual machine's disk image holds a whole operating system plus its apps and files, and VM **snapshots** keep extra copies of changed data. Images also tend to grow and not shrink on their own.

To reclaim space: delete snapshots you don't need inside the VM app, delete files inside the guest system, then use the app's reclaim or compact option; remove VMs you no longer use; or keep VMs on a fast external SSD. Exclude VM files from Time Machine if they make backups huge.