Backspace — Duplicacy Backups Made Easy

A friendly desktop GUI for Duplicacy. The whole philosophy: setting up a backup is three steps, restoring a file is three steps. If you can count to three, you can use Backspace.

Pick the folders you care about, pick where the backups should live (local folder, external drive, SMB share, Dropbox, OneDrive, Google Drive, or any S3-compatible storage), set a schedule, and forget about it. One .exe, one config folder, zero shell scripting.

Encrypted, deduplicated, fully under your control. Powered by the rock-solid Duplicacy CLI.

⚠️ No warranty. Backup software is "AS IS". Backspace may fail to run, miss schedules, or fail to restore. The authors are not liable for any data loss, business interruption, or other damage. You are responsible for verifying your backups, periodically testing restores, and keeping redundant copies of important data (the 3-2-1 rule: three copies, two media, one offsite). See LICENSE for the full terms — by using the software you accept them.

Status

Backspace is functional and covers the everyday backup loop end-to-end — configure, schedule, monitor, restore. It hasn't accumulated enough real-world mileage to call itself stable yet; broader use will surface the rough edges that one developer's machine never hits. Help us shake those out by trying it and reporting anything that surprises you.

• Tested on Windows 11. The full feature set works on the author's setup and against the standard cloud providers. It may well run on Windows 10 too — no one has tried.
• No testing on macOS or Linux yet. The code targets both via Avalonia and there's no architectural reason it shouldn't run — but no one has actually launched it there. If you do, please file an issue with what you saw.
• Issues, PRs, and field reports are very welcome.

The original author is now focusing on a successor project, Backspace, an Avalonia desktop GUI built around Restic instead of Duplicacy. Backspace is not deprecated — Duplicacy is still an excellent engine and Backspace is a perfectly serviceable way to use it. If you'd like to take Backspace forward as a maintainer, open an issue.

Screenshots

See the project website for the full visual tour. A few highlights:

Watch a backup run

Every backup at a glance. Status, last run, next run, source, destination — and a live progress bar while one is running.

Set up your first backup in three steps

Pick a folder, pick a destination, pick a schedule. The wizard walks first-time users from cold install to first backup in under a minute.

Restore exactly what you need

Browse a snapshot, tick the files you want back, choose where they go. Parallel downloads with per-file retry — one slow file doesn't block the rest.

What it does

• Destinations: local folder, external drive (with volume-name matching — backups skip gracefully when the drive isn't plugged in, not fail), SMB / network share, Dropbox (app-scoped), OneDrive (personal + Business), Google Drive, S3-compatible (Wasabi, Cloudflare R2, MinIO, Backblaze-B2-via-S3).
• Filters: edit Duplicacy's filter syntax with a live simulation pane that shows exactly which files would be included or excluded before you run.
• Scheduling: per-platform native scheduler integration — Windows Task Scheduler on Windows, launchd user agents on macOS, systemd user timers on Linux. No always-on process; the app only runs when you open it or a scheduled job kicks in.
• Metered-network guard: folded in-process on Windows (the only OS that exposes a first-class metered-network signal). If your laptop switches to a metered connection mid-backup, the run aborts cleanly instead of eating your data plan. The toggle is hidden on macOS / Linux.
• Monitoring: Healthchecks.io auto-setup (paste your API key, we create and name the checks for you). Local early-warning via stdout parsing for ERROR / Failed to / access denied. Toast + topmost alert with sound (bypasses Focus Assist for failures by default).
• Email: optional, via Resend (free for 3000 emails/month, API-key only) or Mailgun SMTP.
• Restore: a step-by-step wizard — pick the backup, choose a moment in time, tick the files you want, pick where they land, go. Parallel restore with per-file retry cascade (1s → 5s → 10s → 30s → 60s).
• Destructive actions: "erase destination" and "prune to latest revision" live behind a type-to-confirm dialog.

Quick start

Download

Grab the latest release zip from Releases. Unzip somewhere, double-click Backspace.exe. The executable is portable — no installer required.

First-run

The first time you launch, Backspace walks you through the onboarding wizard: pick a source folder, pick a destination, set a schedule. Three clicks to your first backup. Default schedule is daily at 8 PM with retention "keep daily snapshots for 7 days, weekly for 30, monthly for 90, yearly for 365" — which the wizard lets you customize.

Import from existing Duplicacy

Already using Duplicacy? Settings → Import from existing Duplicacy can read either layout:

• The folder containing your .duplicacy/ directory (plain Duplicacy users)
• A parent folder containing several such repos (the duplicacy-util convention)

We import storage URLs, repository paths, filters, and per-storage threads / keep / prune / check settings. Your existing storage is left untouched — your cloud tokens are NOT imported; Backspace will prompt you to re-authenticate the first time it talks to each destination.

Portability

Everything Backspace creates on disk lives in one folder next to the executable: Backspace.config/. That folder holds config.json, the embedded Duplicacy CLI, run logs, per-backup Duplicacy pref dirs, and an encrypted secrets.bin.

Backing up that folder = backing up your whole setup. Drop the binary and the Backspace.config/ folder on a new machine, re-enter your storage passwords and API keys (the secrets vault is bound to the local machine — DPAPI on Windows, an AES-GCM keyfile on macOS / Linux — so it doesn't travel), and you're back in business. Your backup definitions — names, sources, destinations, filters, schedules — travel losslessly.

Building from source

Requires .NET 10 SDK. The project multi-targets net10.0-windows10.0.19041.0 (full Win32 stack) and net10.0 (cross-platform fallback used on macOS / Linux).

# Windows — full feature set
dotnet publish src/Backspace -c Release -r win-x64 --self-contained \
  -f net10.0-windows10.0.19041.0
# → bin/Release/net10.0-windows10.0.19041.0/win-x64/publish/Backspace.exe

# macOS — native ARM build (use osx-x64 for Intel)
dotnet publish src/Backspace -c Release -r osx-arm64 --self-contained \
  -f net10.0 -p:PublishSingleFile=true
# → bin/Release/net10.0/osx-arm64/publish/Backspace

# Linux x64
dotnet publish src/Backspace -c Release -r linux-x64 --self-contained \
  -f net10.0 -p:PublishSingleFile=true
# → bin/Release/net10.0/linux-x64/publish/Backspace

Convenience scripts: launch-debug.bat / launch-release.bat on Windows; launch-debug.sh / launch-release.sh on macOS / Linux.

The build auto-downloads the host-platform Duplicacy CLI from gilbertchen/duplicacy releases the first time it can't find src/Backspace/Assets/duplicacy(.exe), and embeds it into the single-file binary. To build offline, either drop the binary in manually or pass -p:SkipDuplicacyDownload=true.

Running from the command line

Backspace                          # launch GUI
Backspace --run <backup-name>      # unattended single-backup run (scheduler entry point)
Backspace --run-all                # unattended, all enabled backups
Backspace --migrate <path>         # one-off import from an existing Duplicacy setup
Backspace --version

License

Backspace is open-source software released under the MIT License — see LICENSE for the legal text.

Backspace itself is free for any use, including commercial: install, run, modify, redistribute, embed, fork, host as a service. The only thing the MIT license asks is that the copyright + permission notice stays with copies you redistribute.

The bundled duplicacy.exe has its own separate license

Backspace wraps the official Duplicacy CLI by Acrosync, which is distributed under its own terms:

• Free for personal use — individuals using Duplicacy on their own machines for personal data.
• Commercial use requires a paid license from Acrosync, see duplicacy.com/customer_portal.

The MIT license on Backspace does not, and cannot, grant you any rights to the bundled Duplicacy binary. The two are independent.

Bring your own duplicacy.exe

If you'd rather use a Duplicacy build you've downloaded yourself (newer CLI version, custom fork, or a copy you've licensed separately), point Backspace at it via Settings → Duplicacy binary → Use a custom path. The custom path is used in preference to the bundled copy. Helpful if Acrosync ships a CLI fix faster than this repo cuts a new release.

Acknowledgments

• Duplicacy by Acrosync — the engine that does the hard part.
• Avalonia — the cross-platform UI framework.