Three properties that most copy-and-paste backups lack: data is encrypted before it leaves the machine, snapshots store only what changed, and the archive can be checked whenever you like.

Running out of backup space? The deduplication in BorgBackup is the direct answer: identical chunks are stored once, incremental runs finish quickly, storage use drops by a wide margin, encryption and compression come together, and the open source command line approach has been trusted by server administrators for years.

Kopia is an open source backup tool that keeps snapshots, encrypts data before it leaves the machine and stores it on almost any backend, with both a graphical front end and a command line interface.

Duplicati is a free, open-source backup tool that encrypts with AES-256 on the machine before anything leaves it, then uploads blocks to storage you already own: object storage, WebDAV, an FTP server, even a local disk. The 2.4 stable release, out on 3 September 2026, extends whole-disk imaging from Windows to Linux and macOS, adds a one-way sync mode and verifies volumes against bit rot.

A closer look at the recovery pair: TestDisk restores partitions and keeps file names, while PhotoRec ignores the file system and carves data by signature, so a formatted partition can still give files back. This covers the 7.3 development line and the options that change the result.

TestDisk and PhotoRec 7.2 were released on 2024-02-22 and are entirely free and open source. The first specialises in repairing partition tables and finding lost partitions, the second pulls files out of damaged media by signature.

Clonezilla is an open source disk imaging and cloning program that reads and writes only the blocks in use, so images come out smaller and backups finish sooner. It covers ext4, NTFS, APFS and more, and suits disk swaps as well as bare metal backup.