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Backup · head to head

Proxmox Backup Server vs Spanning Backup

Proxmox Backup Server logo

Proxmox Backup Server

Backup

Deduplicating backup server for virtual machines, containers and Linux hosts, with verification built in

From
Free
Rated
-
Full reviewWebsite
Spanning Backup logo

Spanning Backup

Backup

SaaS backup for Google Workspace and Microsoft 365

From
$4/month
Rated
-
Full reviewWebsite

The short version

  • Only Proxmox Backup Server has a free tier, so it costs nothing to try first.
  • Each has a real cost: Proxmox Backup Server there is no Windows client, so physical Windows machines must be backed up by something else and the estate ends up with two backup products.; Spanning Backup no pricing published; requires quote request
  • They diverge on capability: Proxmox Backup Server covers Deduplicated chunk store, Spanning Backup covers Automated daily backup.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Proxmox Backup Server and Spanning Backup actually diverge.

Attributes where Proxmox Backup Server and Spanning Backup differ
AttributeProxmox Backup ServerSpanning Backup
Starting priceFree$4/month
Pricing modelOpen source, no licence feesubscription
Free tierYesNo
PlatformsLinuxCloud SaaS
FoundedUnknown2010

Identical on both: 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 Proxmox Backup Server

  • Deduplicated chunk store
  • Incremental guest backups
  • Client side encryption
  • Verification jobs
  • Remote sync
  • Live restore and file level restore

Only in Spanning Backup

  • Automated daily backup
  • Point-in-time restore
  • Cross-user restore
  • eDiscovery
  • Unlimited storage
  • Admin delegation
  • Google Workspace
  • Microsoft 365

What people use each for

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

Proxmox Backup Server

  • Backing up a Proxmox VE cluster with incremental block level backups of running guestsnot Spanning Backup
  • Replacing a backup product whose licence is priced per socket or per terabyte on a virtualisation estatenot Spanning Backup
  • Proving backup integrity on a schedule rather than discovering corruption during a restorenot Spanning Backup
  • Keeping an encrypted second copy on a remote server or on tape without a third party servicenot Spanning Backup

Spanning Backup

  • SaaS backup and recoverynot Proxmox Backup Server
  • Microsoft 365 backupnot Proxmox Backup Server
  • Google Workspace backupnot Proxmox Backup Server
  • Salesforce backupnot Proxmox Backup Server

Where each one falls short

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

Proxmox Backup Server

  • There is no Windows client, so physical Windows machines must be backed up by something else and the estate ends up with two backup products.
  • The datastore is millions of small chunk files, so it needs storage with real input and output capability and performs poorly on a single spinning disk or an SMB or NFS share.
  • Deduplication is per datastore, so splitting workloads across datastores for retention or tenancy reasons multiplies the storage those workloads consume.
  • Garbage collection depends on file access time semantics on the underlying filesystem, so a datastore mounted with the wrong options can fail to reclaim space or, worse, behave unpredictably.
  • Subscriptions are priced per CPU socket per year, so a backup server consolidated onto fewer larger dual socket machines pays twice per host for the supported repository.

Spanning Backup

  • No pricing published; requires quote request
  • Pricing is customizable based on data volume and service changes

Pricing, plan by plan

Proxmox Backup Server

Free
  • No subscriptionFree
    • Full functionality with no capacity limit
    • Community package repository
    • Community forum support
  • Subscription$undefined/year
    • Priced per CPU socket per year
    • Access to the enterprise package repository
    • Vendor support tickets

Spanning Backup

$4/month
  • Spanning Backup$4/month
    • Daily backup
    • Point-in-time restore
    • Unlimited storage

Which should you pick?

Choose Proxmox Backup Server if

  • You need deduplicated chunk store.
  • You want to start without paying.
  • You work on Linux.
  • You also want incremental guest backups.
Proxmox Backup Server review

Choose Spanning Backup if

  • You need automated daily backup.
  • You work on Cloud SaaS.
  • You also want point-in-time restore.
Spanning Backup review

Questions people ask

Is Proxmox Backup Server or Spanning Backup better?
Neither clearly leads. Proxmox Backup Server starts at Free and Spanning Backup at $4/month, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Proxmox Backup Server or Spanning Backup?
Proxmox Backup Server has a free tier; the other does not. Paid plans start at Free for Proxmox Backup Server and $4/month for Spanning Backup.
Does Proxmox Backup Server or Spanning Backup run on more platforms?
Proxmox Backup Server runs on Linux. Spanning Backup runs on Cloud SaaS.
Can I use Proxmox Backup Server for free?
Yes. Proxmox Backup Server has a free tier, so you can try it without paying. Spanning Backup starts at $4/month.
What is Proxmox Backup Server best used for?
Proxmox Backup Server is most often used for backing up a proxmox ve cluster with incremental block level backups of running guests, replacing a backup product whose licence is priced per socket or per terabyte on a virtualisation estate, proving backup integrity on a schedule rather than discovering corruption during a restore, keeping an encrypted second copy on a remote server or on tape without a third party service. Of those, backing up a proxmox ve cluster with incremental block level backups of running guests and replacing a backup product whose licence is priced per socket or per terabyte on a virtualisation estate are not what Spanning Backup is typically brought in for.
What can Proxmox Backup Server do that Spanning Backup cannot?
Proxmox Backup Server covers Deduplicated chunk store, Incremental guest backups, Client side encryption, Verification jobs. Spanning Backup covers Automated daily backup, Point-in-time restore, Cross-user restore, eDiscovery.

Answered from the vendors’ own pages

Proxmox Backup Server: Can it back up machines that are not on Proxmox?

Linux hosts yes, through the client, at file level. Other hypervisors and physical Windows machines are outside its scope.

Spanning Backup: How much does Spanning Backup cost?

Spanning Backup does not publish pricing online. The company offers FLEXspend, a feature that gives complete flexibility in adjusting backup spend based on data changes. Customers must request a quote through their pricing page.

Source
Proxmox Backup Server: Is a subscription required?

No. Without one you use the community repository and forum support. The subscription buys the tested enterprise repository and vendor tickets.

Spanning Backup: Does Spanning Backup offer a free trial?

Yes, Spanning Backup offers a free trial. Customers can also book a call or request a demo to discuss their specific backup needs and receive a custom quote.

Source
Proxmox Backup Server: How do I know a backup will restore?

Run verification jobs. They re-read the stored chunks and mark snapshots verified or failed, which is stronger evidence than a successful backup log.

Spanning Backup: What products does Spanning Backup cover?

Spanning Backup provides backup solutions for Microsoft 365, Google Workspace, and Salesforce with customizable pricing based on organizational needs.

Source
Proxmox Backup Server: What storage should the datastore be on?

Local disks, ideally with ZFS and enough input and output capacity for many small files. Network shares are supported but routinely disappointing.

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