Tarsnap
by Tarsnap
What Tarsnap is
Tarsnap is a paid command-line online backup service for Linux, BSD, macOS, and other UNIX-like systems. It backs up and restores files, with installation paths for Linux distributions, FreeBSD, NetBSD, OpenBSD, macOS, and Windows Subsystem for Linux. Before uploading archives, the client removes duplicate variable-length data blocks, reducing encoded storage and transmitted data. Each archive is independent, with no stated arbitrary limits on archive count, creation frequency, or retention duration. Client key files hold separate authentication and encryption keys; Tarsnap says the service cannot disclose or tamper with archive data even if compromised. Passphrase protection can use scrypt, and restricted keys can limit actions. Source code is available for review but is not under an open-source license. Archived data uses Amazon S3 and servers use Amazon EC2. Storage and bandwidth are prepaid usage charges at $0.25 a month, measured per GB-month or GB transmitted. A $5 or greater deposit is required before use.
Who it suits
It suits technically oriented users and organizations wanting command-line, encrypted file backups with usage-based storage and bandwidth billing.
What it does well
- Deduplicates variable-length data blocks
- Uses separate authentication and encryption keys
- Has no stated archive-count limits
- Supports several Unix-like platforms
- Offers prepaid usage-based billing
What to know first
- No free plan
- Requires a $5 or greater deposit
- Source code is not open-source licensed
- Account can be removed after prolonged negative balance
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| Storage | $0.25 / GB-month · Prepaid usage-based storage · Charged on encoded data after deduplication, compression, and encryption | $0.25 a month |
| Bandwidth | $0.25 / GB · Prepaid usage-based bandwidth · Charged on encoded data transmitted | $0.25 a month |
| Pay-as-you-go bandwidth | Prepaid; usage based · Encoded data transmitted after deduplication, compression, and encryption · no fixed or minimum monthly fees | $2,500.25, paid once |
| Pay-as-you-go storage | Prepaid; usage based · Encoded data stored after deduplication, compression, and encryption · no fixed or minimum monthly fees | $2,500.25 a month |
As tarsnap.com lists them, read 20 Sept 2026. The maker's own page has the final word.
Verdict
Tarsnap focuses on command-line file backup with client-side key controls, deduplication, and independent archives. Its prepaid storage and bandwidth model requires monitoring encoded usage and account balance.
Facts from Tarsnap's own pages
- Account limit
- If the account balance stays below zero for more than a week, the account is permanently removed. · tarsnap.com, 11 Oct 2026
- Backup scope
- file · tarsnap.com, 20 Sept 2026
- Company history
- The site says Tarsnap Backup Inc. was incorporated in British Columbia, Canada, in September 2011. · tarsnap.com, 11 Oct 2026
- Computer backup
- Yes · tarsnap.com, 20 Sept 2026
- Deduplication
- The client removes duplicate variable-length data blocks before uploading archives, reducing storage and bandwidth use. · tarsnap.com, 11 Oct 2026
- Encryption
- Tarsnap uses client key files containing separate authentication and encryption keys, and says the service cannot disclose or tamper with archive data even if compromised. · tarsnap.com, 11 Oct 2026
- Founded
- Work on Tarsnap began in September 2006, according to the company’s about page. · tarsnap.com, 11 Oct 2026
- Integrations
- Tarsnap uses Amazon S3 for archived data and Amazon EC2 for its server, and uses Stripe and PayPal for payment processing. · tarsnap.com, 11 Oct 2026
- Key protection
- Key files can be passphrase-protected using the scrypt key derivation function, and restricted key files can limit permitted actions. · tarsnap.com, 11 Oct 2026
- Payments
- Users must deposit $5 or more before using Tarsnap and can add money whenever they want. · tarsnap.com, 11 Oct 2026
- Supported platforms
- linux,macos,windows · tarsnap.com, 20 Sept 2026
- Platform support
- The download page provides installation paths for Linux distributions, FreeBSD, NetBSD, OpenBSD, macOS, and Windows Subsystem for Linux. · tarsnap.com, 11 Oct 2026
- Product
- Tarsnap is a secure, efficient command-line online backup service for Linux, BSD, macOS, and other UNIX-like operating systems. · tarsnap.com, 11 Oct 2026
- Restore modes
- file · tarsnap.com, 20 Sept 2026
- Snapshots
- Each archive acts independently, and the site says there are no arbitrary limits on archive count, creation frequency, or retention duration. · tarsnap.com, 11 Oct 2026
- Source code
- The client source code is available for review, but Tarsnap states that it is not distributed under an open source license. · tarsnap.com, 11 Oct 2026
- Paid from
- 0.25 · tarsnap.com, 20 Sept 2026
- Support
- The site lists documentation, an EFnet #tarsnap IRC channel, mailing lists, and contacting the author as support options. · tarsnap.com, 11 Oct 2026
Where Tarsnap stands on Freedom251
- Backup software#125 of 151
- Cloud storage#63 of 66
- Cloud Storage Services#63 of 64