Dedup across everything you own
Not just inside one repository. Each new drive is checked against everything already indexed. Hardlinks and symlinks are accounted for, so reclaim figures are real.
Features
The intelligence other backup tools leave out.
Borg, restic and Time Machine are excellent vaults. BackDown adds the layer that tells you what you're actually storing.
Works todayIn developmentPlannedBackDown is in beta, so each feature is marked with its status.
Proof a drive is safe to wipe
Either every file has a SHA-256-identical copy elsewhere, or you get the list of files that don't. Every copy and deletion is journaled against a verified hash.
Survives bad hardware
Long jobs pick up where they stopped: hashing, copying and rescues never redo finished work. A drive that drops out mid-scan is scanned again when it's back, and hashing reads one file at a time per file system, so a disk never thrashes.
A web UI you'll actually open
Live progress, interactive size trees, duplicate tables and per-drive verdicts, served locally by the daemon, in light and dark.
Go back to any scan
Every scan is kept, so the file browser can show any folder as it was on any scan date, with previews and read-only viewers for PDFs, office documents, SQLite databases, git history and diffs.
Knows what things are
Maildirs, Time Machine sets, phone backups, home directories, disk images, git repos, SQL dumps and cloud exports, each with a date range and size. Regenerable caches are flagged, and can be left out.
Knows where it came from
BackDown reads the rsync scripts, sync markers and backup metadata that record your data's history. It can say "rsynced from your mail server on 31 May 2020," not just "some files."
Browse without restoring
Mailboxes appear as threaded mail, photos as a gallery, SQL dumps as schemas. Disk images open read-only, no mounting needed. Search every backup and drive at once.
Rescans in seconds
After the first scan, BackDown asks the drive's own change log what's changed: the FSEvents history on macOS or the USN journal on Windows, even after the drive was unplugged. On NTFS drives it can also read the master file table directly, listing millions of files in seconds. Anything the log can't vouch for is scanned in full, so nothing is missed. Free in every edition.
Scheduled, encrypted backups
Content-defined chunking, zstd compression and client-side encryption, verified on a schedule, to local disks, SFTP, S3 or B2.
A chain of custody
Signed, append-only manifests of every copy, move and delete, a record you can hand to an auditor or a court.
Privacy
Your data stays on your disks.
Most backup services start by uploading everything. BackDown starts from the opposite end.
No network by default
The local edition makes no network requests. It needs no account and sends no telemetry.
Never writes to a source
BackDown never writes to a drive it's analysing, and drives it mounts for you are mounted read-only, so a flaky enclosure can't corrupt the data you're trying to save.
Never deletes without proof
Nothing is removed unless a copy with a matching hash is already in the journal.
Cloud is opt-in
The optional team dashboard sees metadata only. Your files leave your machines only if you add a cloud backup target.
Hear when 1.0 is out.
The 1.0 beta is out now for Linux, macOS and Windows. Leave your email and we'll send one message when the final version is out.
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