Softwr

Backup · head to head

Kopia vs Windows Backup

Kopia logo

Kopia

Backup

Open source deduplicating backup with client side encryption and a repository on almost any storage

From
Free
Rated
-
Full reviewWebsite
Windows Backup logo

Windows Backup

Backup

Built-in backup and recovery for Windows

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Kopia space is only reclaimed when maintenance runs, and in a shared repository full maintenance is owned by one client, so if that machine goes away the repository grows for ever while every backup still reports success.; Windows Backup folder backup goes to OneDrive, and a free Microsoft account comes with only 5 GB of OneDrive storage
  • They diverge on capability: Kopia covers Content defined chunking, Windows Backup covers File History.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Kopia and Windows Backup actually diverge.

Attributes where Kopia and Windows Backup differ
AttributeKopiaWindows Backup
Pricing modelOpen source, no licence feefree
PlatformsLinux, macOS, Windows, DockerWindows
FoundedUnknown1975

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (Backup).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Kopia

  • Content defined chunking
  • Global deduplication
  • Pack blobs
  • Client side encryption
  • Desktop and command line
  • Repository verification

Only in Windows Backup

  • File History
  • System image backup
  • OneDrive integration
  • System restore points
  • Reset this PC
  • Recovery drive
  • OneDrive
  • Windows Server

What people use each for

The jobs each tool is most often brought in to do.

Kopia

  • Backing up laptops and workstations to cheap object storage with a desktop interface rather than a cron jobnot Windows Backup
  • Deduplicating backups of several similar machines into one repository so common content is stored oncenot Windows Backup
  • Replacing a chunk based tool whose per object charges made a cheap bucket expensivenot Windows Backup
  • Keeping an encrypted offsite copy where the storage provider must never be able to read the contentsnot Windows Backup

Windows Backup

  • Moving folders, settings and app list to a new Windows PCnot Kopia
  • Basic personal file backup for a Windows home usernot Kopia

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Kopia

  • Space is only reclaimed when maintenance runs, and in a shared repository full maintenance is owned by one client, so if that machine goes away the repository grows for ever while every backup still reports success.
  • The repository format has changed across versions and mixing client versions against one repository is discouraged, so a fleet must be upgraded together rather than machine by machine.
  • There is no central orchestration or reporting for many machines, so monitoring a fleet means building your own alerting around exit codes.
  • Restoring many small files is slower than the backup was, because content must be reassembled from pack blobs, and this is rarely tested until the day it matters.
  • Encryption is client side with no escrow, so a lost repository password means the data is unrecoverable and there is no vendor to appeal to.

Windows Backup

  • Folder backup goes to OneDrive, and a free Microsoft account comes with only 5 GB of OneDrive storage
  • It requires signing in with a Microsoft account rather than a local Windows account
  • Personalization preferences are not backed up if OneDrive storage is insufficient
  • OneDrive folder syncing through Windows Backup is not available for work or school accounts, and Windows does not remember apps for those accounts
  • Device settings sync for a work or school account only if the organization allows it

Pricing, plan by plan

Kopia

Free
  • KopiaFree
    • Full functionality, no data limit
    • Desktop application included
    • Any supported storage back end

Windows Backup

Free
  • Built-inFree
    • File History
    • System image
    • OneDrive sync

Which should you pick?

Choose Kopia if

  • You need content defined chunking.
  • You want to start without paying.
  • You work on Linux, macOS, Windows, Docker.
  • You also want global deduplication.
Kopia review

Choose Windows Backup if

  • You need file history.
  • You want to start without paying.
  • You work on Windows.
  • You also want system image backup.
Windows Backup review

Questions people ask

Is Kopia or Windows Backup better?
Neither clearly leads. Kopia starts at Free and Windows Backup at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Kopia or Windows Backup?
Kopia starts at Free and Windows Backup at Free.
Does Kopia or Windows Backup run on more platforms?
Kopia runs on Linux, macOS, Windows, Docker. Windows Backup runs on Windows.
Can I use Kopia for free?
Both have a free tier, so you can try either at no cost before committing.
What is Kopia best used for?
Kopia is most often used for backing up laptops and workstations to cheap object storage with a desktop interface rather than a cron job, deduplicating backups of several similar machines into one repository so common content is stored once, replacing a chunk based tool whose per object charges made a cheap bucket expensive, keeping an encrypted offsite copy where the storage provider must never be able to read the contents. Of those, backing up laptops and workstations to cheap object storage with a desktop interface rather than a cron job and deduplicating backups of several similar machines into one repository so common content is stored once are not what Windows Backup is typically brought in for.
What can Kopia do that Windows Backup cannot?
Kopia covers Content defined chunking, Global deduplication, Pack blobs, Client side encryption. Windows Backup covers File History, System image backup, OneDrive integration, System restore points.

Answered from the vendors’ own pages

Kopia: Is a partly corrupt repository still restorable?

Partly. Deduplication means one damaged pack blob affects every snapshot referencing its contents, but unaffected files still restore. Run verification regularly rather than assuming.

Windows Backup: How much cloud storage do I get with Windows Backup?

Your Microsoft account includes 5 GB of free OneDrive cloud storage. "More storage is available to purchase if you need it" for users requiring additional capacity.

Source
Kopia: How does it compare with restic?

Similar guarantees, with packing that behaves better on per operation billing, a desktop interface, and compression enabled by default.

Windows Backup: What types of Microsoft accounts are supported by Windows Backup?

Windows Backup works exclusively with personal Microsoft accounts (such as those ending in @outlook.com or @live.com). The service explicitly does not support work or school accounts at this time.

Source
Kopia: Do I need to run maintenance manually?

It is scheduled automatically by default, but you must ensure the client that owns full maintenance keeps running, otherwise deleted snapshots never free space.

Windows Backup: Can I restore my backup to a different PC?

Yes. When setting up a new device, simply sign in with the same Microsoft account used to create the original backup. "If you have more than one PC backed up, you can select More options and select the backup you wish to restore from."

Source
Kopia: Can several machines share one repository?

Yes, and that is where deduplication pays off, but they should run compatible versions and only one owns full maintenance.

Windows Backup: How do I delete my backed-up data if I no longer want it stored?

Visit your Microsoft Account Devices page, locate the Cloud synced settings section at the bottom, and select 'Clear stored settings' to delete previously backed-up data from your account.

Source
Windows Backup: Which folders and settings can I choose to back up?

You can selectively back up Desktop, Documents, Pictures, Videos, and Music folders, plus settings including apps, accessibility, accounts, Wi-Fi passwords, personalization, and language preferences.

Source
Share

Related pages

More on Kopia

More on Windows Backup

Keep looking

Other head to heads