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Kopia
Apache-2.0Kopia replaces Backblaze with fast deduplication, client-side encryption, and BYO cloud storage across Linux, macOS, and Windows.
Open-source alternative to — compare it against:
Overview
Software engineer Jarek Kowalski started Kopia to create a fast, modular backup engine that handles encrypted cloud snapshots without heavy dependencies. Built in Go, the project decoupled backup logic from storage backends, allowing machines to stream deduplicated data directly into any object store. That origin gives developers and DevOps engineers today a scriptable engine for automated infrastructure and workstations without proprietary lock-in.
Why Kopia instead of Backblaze
Backblaze Computer Backup runs as a desktop daemon uploading drives to Backblaze's managed cloud on fixed schedules. That model simplifies personal backups, but creates friction in engineering environments: it lacks a Linux client, cannot be triggered from CI/CD runners or shell scripts, and enforces rigid file rules. Kopia decouples the snapshot engine from storage. A single Go binary runs as a CLI or GUI across Linux, macOS, and Windows, streaming snapshots to Backblaze B2, Amazon S3, Google Cloud Storage, or SFTP targets.
Operational control diverges around snapshot retention and encryption keys. Backblaze treats backups as continuous sync with limited version history unless users pay for extended retention. Kopia organizes backups into immutable, point-in-time snapshots governed by granular retention policies applied globally or per path. Developers configure .kopiaignore files to skip build artifacts like node_modules, schedule hourly snapshots, and execute action hooks for database dumps. In exchange, Kopia requires provisioning storage and managing repository keys, with zero vendor escrow if passwords are lost.
What it does well
- Content-addressable deduplication: splits files using rolling hashes, uploading unique chunks once across directories and machines to reduce storage costs.
- Client-side encryption: protects snapshots and metadata with AES-256-GCM or ChaCha20-Poly1305 before transmission, ensuring zero-knowledge privacy on untrusted cloud providers.
- Broad backend support: connects natively to Backblaze B2, Amazon S3, Azure Blob, Google Cloud Storage, SFTP, WebDAV, and local storage.
- Automation-ready interfaces: provides a CLI for scripting and systemd timers, a desktop GUI, and a repository server with a JSON API.
- Granular snapshot policies: manages retention windows, compression algorithms (zstd, s2, pgzip), and directory exclusion files (.kopiaignore) hierarchically.
