shouldiuse.io

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Should I Use Kopia?

kopia.io·Analyzed 1 week ago··Based on 10 sources

Fast and Secure Open-Source Backup Software for Windows, Mac, and Linux

Verdict

Worth it

Free, fast, encrypted open-source backup that technical users and self-hosters love.

Confidence: Medium

Skip it if you want vendor support, or run a server you won't keep patched.

Free, fast open-source backup loved by self-hosters — but patch the server RCE before exposing anything.

Key stats

  • Value for money: 5/5

    Rating

  • $0

    Starting price

  • 10

    Sources

  • Analyzed

  • Value for money: 5/5. Free, unlimited, open-source
  • Ease of use: 3/5. Desktop GUI helps; defaults reportedly cause failures
  • Feature depth: 5/5. Encryption, dedup, compression, ransomware mode, many backends
  • Support quality: 2/5. Community forums only; no paid support
  • Security posture: 3/5. Strong encryption; critical server RCE in 2026
  • $0 Price Fully open-source, all features free
  • Yes Free tier No paid tiers; costs are your storage backend
  • 1 Known critical CVEs CVE-2026-45695, fixed in 0.23.0
  • 3 Platforms Windows, macOS, Linux

Pricing

Open Source

$0

  • Unlimited backups on Windows, Mac, Linux
  • Encryption, dedup, compression, ransomware mode
  • Community support only
Best for and not for

Best for

  • Self-hosters and NAS owners
  • Multi-OS households and small offices
  • Developers backing up to S3/B2
  • Privacy-focused users wanting encrypted dedup

Not for

  • Non-technical users wanting set-and-forget backups — use Backblaze or Time Machine
  • Businesses needing vendor SLAs and support contracts
  • Anyone who won't promptly patch an internet-exposed Kopia server
  • Guess: enterprises needing certified compliance and managed backup

Biggest gotcha

  • highPatch to 0.23.0+ before running Kopia server; unauthenticated RCE (CVE-2026-45695)
  • highNever expose the Kopia server to the public internet unauthenticated⁶
  • mediumFree software, but you pay for storage backend (S3, B2) and your time10
  • mediumDefault settings have caused silent backup failures — verify your first restore⁸

Pros

  • Completely free and open-source, no paid tiers²
  • Users call it the fastest backup tool they've tried⁴
  • Cross-platform with a user-friendly desktop app¹
  • Encryption by default plus ransomware-resistant backup mode
  • Backs up to many targets including cloud object storage

Cons

  • Critical unauthenticated RCE in server mode (CVE-2026-45695)⁶
  • Reported dangerous default settings caused backups to fail entirely⁸
  • Metadata can leak into logs
  • Some users report performance issues on large datasets

Security

Encrypted by default; one critical server RCE (CVE-2026-45695) fixed in 0.23.0 — run the latest version.

  • CVE-2026-45695 — Unauthenticated RCE via SSH ProxyCommand injectionAffects Kopia server before 0.23.0; rated critical; fixed in 0.23.0.⁷
  • Server mode security concernsUser-reported GitHub issue flags the Kopia server as insecure; forums note metadata leaks to logs.

What users say

Overwhelmingly positive among self-hosters and technical users who praise its speed, with a minority reporting defaults and performance issues.

“Kopia is by far the fastest backup tool I have ever tried”
LowEndTalk
“Kopia is brilliant”
Reddit, r/selfhosted
“Render me a happy guy. I now am an all-in fan”
Reddit, r/selfhosted

Methodology

Based on ~15 usable public sources. Unrelated 'Kopia' entities (kopia.ai, KOPIA agriculture program) excluded.

Sources

  1. official
  2. official
  3. review
  4. review
  5. review
  6. security
  7. security
  8. review
  9. review
  10. review

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