Restic

Restic is a fast, secure, and efficient backup program written in Go that provides encrypted, deduplicated, and incremental backups to local, remote, and cloud storage backends. Created by Alexander Neumann in 2014, Restic has over 27,500 stars as of 2026 and has become one of the most popular open-source backup solutions. Restic's design prioritizes security: all data is encrypted and authenticated using AES-256-CTR for encryption and Poly1305-AES for authentication before leaving the client, with encryption keys derived from user passwords using scrypt. The repository format uses content-defined chunking with variable-size blocks for deduplication, enabling efficient storage of slightly modified files. Key features include: snapshot-based backups (each backup creates an immutable snapshot with timestamp, hostname, and tags), incremental backups (only new or modified chunks uploaded, but each snapshot is a complete view), cross-file and cross-snapshot deduplication (identical blocks stored once), multiple backends (local, SFTP/SSH, Amazon S3, Backblaze B2, Google Cloud Storage, Azure Blob, MinIO, Wasabi, OpenStack Swift, REST server), snapshot retention management (keep last N, daily, weekly, monthly, yearly with automatic pruning), integrity verification via restic check, file-level restore, FUSE mount for browsing snapshots, and data migration between repositories. Version 0.17+, Go 1.22+, licensed under BSD-2-Clause.