Comparison

Kopia vs Duplicati

Kopia lands on Worth it, and Duplicati lands on Depends.

Kopia

Worth it

Confidence: Medium

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

Depends

Confidence: Medium

Buy if you're technical and want free, encrypted backups to your own cloud storage . and you'll patch promptly.

Kopia versus Duplicati
Compare	Kopia	Duplicati
Verdict	Worth it	Depends
Best for	Self-hosters and NAS owners	Self-hosters and homelab users
Who it's not for	Non-technical users wanting set-and-forget backups . use Backblaze or Time Machine	Non-technical users wanting set-and-forget backup
Privacy	Encrypted by default; one critical server RCE (CVE-2026-45695) fixed in 0.23.0 . run the latest version.^⁷	Encryption design is solid (AES-256, zero-trust), but 2026 advisories mean you must run the latest patched version.¹⁶
Support quality	Community forums only; no paid support	Community forum only; no vendor support on free tier
Public sentiment	Overwhelmingly positive among self-hosters and technical users who praise its speed, with a minority reporting defaults and performance issues.^³	Reviews are split: many call it powerful and unfairly criticized, while others report reliability problems severe enough to switch away.¹⁴
Biggest gotcha	Patch to 0.23.0+ before running Kopia server; unauthenticated RCE (CVE-2026-45695)	v2.3.0.1 has a published CERT alert (VU#847406) . run only the latest release¹⁶

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