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. Kopia official sitekopia.io
    official
  2. Kopia GitHub repositorygithub.com
    official
  3. Kopia is brilliant : r/selfhostedreddit.com
    review
  4. Kopia is by far the fastest backup tool — LowEndTalklowendtalk.com
    review
  5. MakeUseOf: open-source backup reviewmakeuseof.com
    review
  6. Kopia Backup RCE Vulnerability — Orca Securityorca.security
    security
  7. CVE-2026-45695 — NVDnvd.nist.gov
    security
  8. Dangerous default settings cause backup failures — GitHub issuegithub.com
    review
  9. Duplicati vs Duplicacy vs Kopia vs Vorta comparisonforum.duplicati.com
    review
  10. macOS backups with Kopia and Backblazehmarr.com
    review

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