Tarsnap - Online backups for the truly paranoid

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Online backups for the truly paranoid

Tarsnap is a secure, efficient online backup service:

  • Encryption: your data can only be accessed with your personal keys.
  • Source code: the client code is available.
  • Deduplication: only the unique data between your current files and encrypted archives is uploaded.

Tarsnap runs on UNIX-like operating systems (BSD, Linux, MacOS X, Cygwin, etc).

Tarsnap pricing

Tarsnap uses a prepaid model based on actual usage:

Storage: 250 picodollars / byte-month of encoded data
($0.25 / GB-month)
Bandwidth: 250 picodollars / byte of encoded data
($0.25 / GB)

There are no other fees — Tarsnap has no fixed costs or minimum monthly fees.

Why use Tarsnap?

Dataflow chart of a typical backup with Tarsnap

Consider a typical backup scenario:

  • Alice begins a backup, which takes a complete snapshot of her files.
  • Tarsnap automatically finds the unique data within her files.
  • Alice pays less than $5/month.
  • Alice's data is secure.

Latest Tarsnap release

Tarsnap 1.0.39 (July 29, 2017)

Changes in this version compared to 1.0.38:

  • tarsnap 1.0.38 (but not earlier versions) would exit with an assertion failure after successfully creating an archive containing a file with "last modified" times prior to January 1st, 1970.
  • tarsnap 1.0.38 and earlier could crash if instructed to archive the contents of corrupt cpio or ar archives (via the @archive directive).
  • tarsnap 1.0.38 and earlier could crash if passed an invalidly encrypted key file.

You can see all of the changes between 1.0.38 and this version in our tarsnap git repository.