Restic vs Tarsnap
why long-time Tarsnap users are switching

Quick summary

• Choose Restic if:You want predictable flat pricing, broad backend choice (SFTP, S3, B2, Azure, GCS), and active development with a large community.
• Choose Tarsnap if:You back up small amounts of high-value data, value cryptographer-grade rigor over price, and the per-byte billing actually works in your favor.

Side-by-side comparison

The pricing reality

Tarsnap's per-byte model made sense in 2008 when storage was expensive and clouds didn't compete on price. In 2026 it's the single biggest reason people switch. A 100 GB backup on Tarsnap costs around $25/month if your dedup ratio is 1:1 (better dedup = less). The same 100 GB on a Restic-over-SFTP host like ServerCrate is $5/month flat with no math required.

The picodollar pricing isn't a gimmick — it's mathematically honest billing. But for most workloads it ends up more expensive than flat-rate hosting, especially once bandwidth charges enter the picture during a real restore.

Encryption and security

Both tools encrypt client-side before upload. Neither vendor (Tarsnap or your Restic host) can read your data. The cipher choice is different but both are considered secure: Tarsnap uses Twofish-CTR with HMAC-SHA256 in a custom construction designed by Colin Percival, who also created scrypt. Restic uses AES-256-CTR with Poly1305-AES authentication, an industry-standard construction.

For paranoia-grade workloads (security keys, financial records, legal documents), both are appropriate. For everyday backup use, the difference is academic — neither has known practical attacks.

Backend flexibility

This is Restic's biggest advantage. You can point it at SFTP, Amazon S3, Backblaze B2, Azure Blob, Google Cloud Storage, or anything rclone supports. If your provider goes bad, you change one config line and use someone else.

Tarsnap is the service. The client only talks to Tarsnap's servers, which run on AWS S3. There is no migration path to a different provider — you have to run a fresh backup somewhere else and let your Tarsnap data age out.

Why people actually switch

The pattern from migration discussions on Hacker News, the Tarsnap mailing list, and r/selfhosted is consistent: people stay on Tarsnap until they have a real cost shock. Usually it's a large restore that runs up a bandwidth bill, or an expanding backup set that pushes the monthly storage cost above what they expected. The encryption isn't the problem — the predictability is.

Restic's flat-pricing hosts solve that. You know what you'll pay each month before you run the backup. If you double your data, you upgrade one tier. If you restore everything, you pay nothing extra.

First-run setup commands, side by side

Here's what you actually type to get a first backup running with each tool. Assume you've installed the binary and have a destination ready.

Restic: three commands to first backup

export RESTIC_REPOSITORY=sftp:user@host:/path/to/repo
export RESTIC_PASSWORD=your-password
restic init
restic backup /etc /home /var/www

That's the whole setup. restic init creates the encrypted repository, restic backup creates a snapshot.

Tarsnap: register, gen key, backup

# After installing tarsnap and prepaying for service:
tarsnap-keygen --keyfile /root/tarsnap.key \
  --user me@example.com --machine my-server
tarsnap -c -f my-first-backup /etc /home /var/www

Tarsnap requires an account with prepaid balance before any backup runs. The tarsnap.key file is the only way to decrypt your data — lose it and your backups are unrecoverable. Same applies to Restic's password.

Single-file restore: how each tool handles it

The workflow you'll run during an actual emergency. Both tools support browsing snapshot contents and pulling specific files.

Restic: mount and cp

mkdir /mnt/backup
restic mount /mnt/backup
cp /mnt/backup/snapshots/latest/home/user/file.txt /tmp/
fusermount -u /mnt/backup

Tarsnap: list and extract

tarsnap --list-archives
tarsnap -x -f my-first-backup home/user/file.txt

Tarsnap's restore is conceptually simple — same command syntax as tar(1) by design. The cost is the bandwidth charge: every byte you restore is billed at egress rate. For Restic with a flat-rate host, restore is free. Full guide: Restic restore guide.