---
id: mac-storage-basics.what-are-local-snapshots-on-a-mac
url: https://storagestudio.us/faq/mac-storage-basics/what-are-local-snapshots-on-a-mac
category: "Mac storage basics"
subcategory: "Purgeable space and local snapshots"
question: "What are local snapshots on a Mac?"
alt_questions:
  - "apfs local snapshots explained"
  - "time machine local snapshots"
  - "what is com.apple.timemachine snapshot"
  - "local snapshots taking space mac"
  - "mac snapshots meaning"
  - "why does my mac keep snapshots"
short_answer: "Point-in-time records of your startup disk kept on the Mac by Time Machine and before updates. They hold the space of changed or deleted files and usually expire within a day."
tags: ["snapshots", "time machine", "apfs"]
related: ["https://storagestudio.us/faq/mac-storage-basics/why-doesnt-deleting-files-free-up-space-on-my-mac", "https://storagestudio.us/faq/mac-storage-basics/how-do-i-delete-local-snapshots-on-a-mac", "https://storagestudio.us/faq/mac-storage-basics/are-local-snapshots-a-backup"]
applies_to: "all"
last_reviewed: 2026-10-01
---

# What are local snapshots on a Mac?

A **local snapshot** is a point-in-time record of your startup disk that macOS keeps on the Mac itself. Time Machine makes them regularly so it can restore recent versions even when your backup drive isn't connected, and macOS makes one before system updates.

A snapshot doesn't copy your files; it simply keeps the blocks of files that have since changed or been deleted. That's why deleting files may not free space immediately — a snapshot may still be holding them.

Time Machine's snapshots normally expire within about a day, and macOS removes them early when space runs low. See [why deleting files doesn't free space](https://storagestudio.us/faq/mac-storage-basics/why-doesnt-deleting-files-free-up-space-on-my-mac).