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OneDrive Files On-Demand: where the bytes actually are

Verified 2 min read

What the three file states mean, why freeing space is not deleting, and what happens to your data when the account goes away.

Tested onPro (26H2) · Build 26300.9457 · x64
E1
Build
26300.9457
Edition
Pro (26H2)
Architecture
x64
Support
Documentation (E1)
Evidence
E1Official documentation
Verified
2026-10-29
Page type
Concept

The short answer

Section titled “The short answer”

With Files On-Demand, a file in your OneDrive folder has three states:

Icon State On disk?
Cloud outline Online-only a placeholder, no content
Green check Locally available content cached, may be evicted
Solid green / pin Always keep on this device content stays

“Free up space” changes the state; it does not delete anything. The file remains in OneDrive and re-downloads when opened.

Why this matters more than it sounds

Section titled “Why this matters more than it sounds”
  • Backup tools that walk the folder may see thousands of placeholder files and back up nothing useful — or trigger a full download.
  • Search tools may not read online-only files.
  • Disk space reporting counts only the states that hold content.
  • Copying the folder to a USB drive silently downloads everything.
Terminal window
# what OneDrive is doing locally
Get-Process OneDrive -ErrorAction SilentlyContinue | Select-Object Id,StartTime
Get-ChildItem "$env:USERPROFILE\OneDrive" -Force -ErrorAction SilentlyContinue |
  Select-Object -First 20 Name,Attributes,Length

Files with the Offline / reparse-point attribute are placeholders; Length may be 0 for an online-only file even though the real file is large.

The three settings that matter

Section titled “The three settings that matter”
  1. Files On-Demand — must be on for placeholders to exist at all.
  2. Always keep on this device — pin what you need offline (a project folder, not the whole drive).
  3. Free up space — evicts content, keeps the placeholder.

The default behaviour — “let Windows decide” — is what produces the surprise: a folder you used last month is empty on a plane.

What happens when the account goes away

Section titled “What happens when the account goes away”

This is the part people learn too late:

  • Signing out of OneDrive does not delete local files, but placeholders become unreadable.
  • Unlinking a work account can remove access to files that were never downloaded.
  • Deleting in OneDrive deletes in the folder, and then in the cloud.

Check before you travel or wipe

Section titled “Check before you travel or wipe”
Terminal window
# force a folder offline-available (pin) - example path
# right-click the folder -> "Always keep on this device"
Get-ChildItem "$env:USERPROFILE\OneDrive" -Recurse -Force -ErrorAction SilentlyContinue |
  Measure-Object -Property Length -Sum |
  Select-Object Count,@{n='GB';e={[math]::Round($_.Sum/1GB,2)}}

That sum counts only content actually on disk. If it is far below what you expect, most files are placeholders.

Section titled “Related”

Lab boundary

Section titled “Lab boundary”

E1. The On-Demand model is documented by Microsoft. The lab VMs do not sign in to a OneDrive account, so no placeholder behaviour was reproduced here.

Sources