Best Open Source Backup Software

How We Evaluated These Tools

We assessed each backup tool across six categories that matter most in real-world deployments: deduplication efficiency, encryption strength, platform support, storage backend flexibility, ease of use, and community health. We weighted platform support and backend flexibility more heavily because these are the factors that most often eliminate candidates before a user even runs their first backup. A tool that does not run on your operating system or connect to your storage provider is irrelevant regardless of its other strengths.

We also considered how actively each project is maintained. Backup software must keep pace with evolving storage APIs, operating system changes, and security vulnerabilities. A tool that has not seen a release in over a year raises legitimate concerns about long-term reliability. All tools listed here had releases within the past 12 months as of June 2026.

Restic: Best Overall

Restic is the most broadly capable open source backup tool available. Written in Go, it compiles to a single static binary that runs on Linux, macOS, Windows, and FreeBSD without dependencies. This simplicity extends to its design philosophy, Restic does one thing well: it creates encrypted, deduplicated snapshots of your data and stores them on any of a dozen supported backends.

Every backup Restic creates is encrypted. There is no unencrypted mode, which means accidental exposure of unprotected backups is impossible. It uses AES-256-CTR for encryption and Poly1305-AES for authentication, a well-audited combination that has withstood years of cryptographic scrutiny. Repository-level integrity checking with the restic check command lets you verify that all data is intact and no corruption has occurred.

Backend support is where Restic separates itself from BorgBackup. It natively supports local directories, SFTP, Amazon S3, Backblaze B2, Microsoft Azure Blob Storage, Google Cloud Storage, OpenStack Swift, and any S3-compatible service including MinIO and Wasabi. This means you can back up to virtually any storage provider without third-party adapters or custom scripting.

Restic's deduplication uses content-defined chunking with the Rabin fingerprint algorithm, breaking files into variable-sized chunks and storing each unique chunk only once. While its deduplication ratio is slightly behind BorgBackup's on certain workloads, the difference is typically less than 10% and is more than offset by Restic's broader platform and backend support.

The community around Restic is the largest of any open source backup tool. Its GitHub repository has over 27,000 stars, and its forum is active with both user support and developer discussion. Comprehensive documentation covers every command and configuration option in detail.

BorgBackup: Best for Storage Efficiency

BorgBackup (often called just Borg) is the most storage-efficient deduplicating backup tool available. Its content-defined chunking algorithm, combined with support for multiple compression algorithms (lz4, zstd, zlib, lzma) at configurable compression levels, consistently produces the smallest backup repositories in head-to-head comparisons.

Borg's compression flexibility is a genuine advantage. You can use lz4 for fast backups with moderate compression, zstd for an excellent balance of speed and ratio, or lzma for maximum compression on archival data. Per-file compression selection based on file type is also supported, so you can compress text files aggressively while leaving already-compressed files like JPEGs and videos untouched.

The main limitation of BorgBackup is its storage backend support. Borg only works with local storage and SSH remotes. There is no native support for S3, B2, Azure, or any other cloud object storage. If you want to back up to Backblaze B2, you need an intermediary tool like rclone to mount the B2 bucket as a local filesystem, which adds complexity and potential failure points. For users who back up to their own servers over SSH, this limitation is irrelevant.

BorgBackup runs on Linux and macOS. There is no official Windows support, and third-party Windows builds are experimental. If you need to back up Windows machines, Borg is not a viable option.

The BorgBackup vs Restic vs Kopia comparison provides a detailed head-to-head analysis of deduplication ratios, backup speeds, and memory usage across these three tools.

Kopia: Best Graphical Interface and Server Mode

Kopia is the most feature-rich of the three major deduplicating backup tools. Like Restic, it is written in Go and supports all major platforms and cloud storage backends. What sets Kopia apart is its built-in web UI, server mode for centralized management, and granular per-directory snapshot policies.

The web UI makes Kopia accessible to users who are not comfortable with command-line tools. You can create repositories, configure snapshot policies, browse backup contents, and restore files, all from a browser. This is a significant advantage for small teams or home users who want a graphical backup management experience without paying for commercial software.

Kopia's server mode lets you run a central Kopia instance that manages backups for multiple machines. Client machines connect to the server, which handles storage, retention, and policy enforcement. This approach sits between the simplicity of standalone CLI tools and the complexity of full client-server systems like Bacula. For a small office with 5-20 machines, Kopia's server mode provides centralized management without the configuration overhead of enterprise backup suites.

Per-directory snapshot policies are unique to Kopia. You can set different retention rules, compression settings, and scheduling intervals for different directories on the same machine. This is useful when you have directories with different backup requirements, such as keeping database dumps for two years while retaining log file backups for only 30 days.

Kopia version 0.23, released in early 2026, brought improved maintenance statistics, content-to-pack consistency checks, and reduced resource usage on Unix systems. The project is actively developed with regular releases.

UrBackup: Best Client-Server Solution

UrBackup is fundamentally different from the three tools above. It is a client-server backup system designed to back up multiple machines over a network to a central server. Where Restic, Borg, and Kopia are standalone tools that you configure on each machine individually, UrBackup provides a centralized dashboard where you manage all your backup clients from one place.

UrBackup's standout feature is its support for both file-level and full disk image backups. File backups protect individual files and directories. Image backups capture the entire disk, including the operating system, boot sectors, and partition layout. This means you can restore an entire machine from bare metal, not just the data files, which dramatically reduces recovery time after a complete hardware failure.

The web administration interface shows the status of every backup client, including last backup time, success or failure, storage consumption, and client version. Email alerts notify administrators of backup failures. The interface is clean and functional, though it lacks the polish of commercial backup dashboards.

UrBackup server version 2.5.37 was released in April 2026. It runs on Linux and Windows servers, with client agents available for Windows, Linux, and macOS. The Windows client integrates with Volume Shadow Copy Service (VSS) for consistent backups of open files and databases. For a detailed walkthrough, see our How to Install UrBackup guide.

Bacula: Best for Enterprise Scale

Bacula is the most mature and scalable open source backup system. Its modular architecture separates the director (scheduling and coordination), storage daemon (media management), and file daemon (client agent) into independent components that can be distributed across multiple machines. This separation allows Bacula to scale to environments with thousands of clients and petabytes of data.

Bacula supports tape libraries with automated changers, disk-based storage pools, and cloud storage backends. Its media management features, including volume rotation, pool-based storage policies, and multi-drive tape library support, are unmatched by any other open source backup tool. For organizations with compliance requirements that mandate long-term tape archival, Bacula is often the only open source option that meets the requirement.

The tradeoff is complexity. Bacula's configuration involves editing multiple text files with a proprietary syntax, and the initial setup is significantly more involved than any of the newer tools. The community edition is fully functional but the web-based management interface (BWeb) is only available in the commercial enterprise edition. Most community users manage Bacula through its command-line console or third-party web interfaces like Baculum.

Duplicati: Best for Home Users

Duplicati targets home users and small businesses who want a graphical, set-and-forget backup solution that sends data to cloud storage. Its web-based interface walks users through backup configuration with a setup wizard, and it supports a uniquely broad range of cloud backends including Google Drive, OneDrive, Dropbox, Amazon S3, Backblaze B2, and many more.

Duplicati supports encryption (AES-256), compression, and deduplication. It is written in C# and runs on Windows natively, and on macOS and Linux through the .NET runtime. While it lacks the performance and deduplication efficiency of Restic or BorgBackup, its accessibility makes it the best choice for non-technical users who want reliable cloud backups without learning command-line tools.

The main concern with Duplicati is its release pace. The project has been in beta for an extended period, and some users report occasional stability issues with large repositories. For critical data, a more mature tool is recommended.

BackupPC: Best Agentless Network Backup

BackupPC backs up Windows, Linux, and macOS machines to a central server without requiring any client software. It uses SMB (for Windows) and rsync (for Linux and macOS) to pull data from network machines, which means you can start backing up existing infrastructure immediately without installing agents on every client.

BackupPC uses file-level pooling and compression to reduce storage requirements. Its web interface allows administrators to browse backups, restore files, and monitor backup status. It can back up machines even when they are behind NAT or firewalls, as long as the server can reach them over the network.

The agentless approach is both BackupPC's greatest strength and its limitation. It simplifies deployment but means you cannot do image-level backups, consistent database snapshots, or VSS-aware file copies that require a client agent. For environments where file-level backup is sufficient, BackupPC is a low-maintenance, proven solution.

Quick Comparison Table