mylocalbackupvideo.mp4
Open-source versioned local backups for Windows. Space-efficient snapshots you can browse and copy back from in File Explorer.
MIT-licensed source code with NTFS hard-link deduplication to keep backup history compact.
Read this first • Download • Features • Restoring files • Good to know • Requirements • Building • License
Free to download and use. Tips are voluntary and don't buy support or a warranty.
Caution
MyLocalBackup is a free personal project. It can lose, overwrite or delete data, including files outside the backup.
- It is provided "as is" under the MIT License, without warranty of any kind. You alone are responsible for how you use it and for any loss that results. See DISCLAIMER.md.
- Versions 0.7.5 to 0.9.16 have known bugs that can delete or overwrite real files. See Known data-loss bugs in older versions. Don't use them.
- Never rely on MyLocalBackup as your only backup. Keep a second, independent copy of anything you can't afford to lose, and check regularly that you can open files from your snapshots.
- There is no support and no promise of fixes. See SUPPORT.md.
MyLocalBackup writes to your backup drive and deletes old snapshots automatically, both on a schedule and when the drive runs low on space. Its snapshots share files through NTFS hard links, which makes mistakes inside a snapshot folder spread to other snapshots. It has not been independently tested or audited. A bug, a wrong setting or a failing disk can mean that the backup you need isn't there. Use it at your own risk, and read Good to know before relying on it.
- Versioned snapshots: Each backup run creates a timestamped folder that looks like a complete copy, but unchanged files are hard-linked to previous snapshots — no duplicate data on disk. This means snapshots share those files; see Good to know.
- Parallel file processing: Files within each directory are processed up to 4 concurrently, significantly reducing backup time on large folders.
- Rename/move detection: Files moved or renamed are matched via size + last-write-time, so they're hard-linked rather than re-copied.
- Background retention: Old snapshot cleanup runs in the background after a backup completes — the UI never hangs at 100%.
- Two-phase deletion: Snapshots are marked
Deletingbefore removal, so a delete that gets cut short (app closed, PC shut down) is finished on the next backup. Folder links inside a snapshot (symbolic links, junctions) are removed as links only; the folders they point to are never touched. - Retention management: Old snapshots are thinned automatically: everything from the last 24 hours is kept, then one per day for 30 days, then one per week. The newest 5 are always kept. When the destination drive is low on space, older snapshots are deleted too (on by default, see Good to know).
- Backup resume: If a backup is interrupted (app close, update, crash), the next run resumes from where it left off — files already copied are skipped. Files that changed in the meantime are copied fresh, and earlier snapshots keep their own versions.
- Destination check: A destination inside one of your source folders is refused, because every backup would copy the earlier backups again.
- Configurable exclusions: Add folder names to
ExcludedFolderNamesinconfig.jsonto skip regeneratable artifacts (e.g.node_modules,bin,obj) and speed up backups of developer workspaces. Empty by default — everything is backed up unless explicitly excluded. - Flush retry with bounded retries: Batch database inserts retry up to 3 times on failure before dropping entries, preventing unbounded re-queuing.
- Interval mode: Every N hours (1–168).
- Daily fixed-time: Runs once per day at a configured time (e.g. 2:00 AM).
- Manual mode: Run on demand only.
- Launch at startup: Optional registry-based auto-start so backups run whenever you're logged in.
- Catch-up logic: If a scheduled backup was missed (app closed), the next run fires soon rather than waiting a full interval.
- Dashboard: Live status, countdown to next backup, progress bar with per-file detail for large files, and a link to the Skipped Files list in Settings (persisted across restarts).
- Backup History: Browse past snapshots, open them in File Explorer, or delete them.
- System tray: Run, pause, resume, or skip backups from the tray context menu. Disable automatic backups directly from tray.
- Notifications: Toast-style notification when a background backup starts (configurable).
- Updates are published through this repository's GitHub Releases tab.
- Download the latest
MyLocalBackupSetup.exeinstaller and run it manually. - Newer installers replace the existing per-user install when the version number increases.
There's no restore button in the app. Every snapshot is a normal folder, so restoring is copy and paste:
- Open History, right-click the backup you want and choose Open in Explorer. (Or browse to
<your destination>\Backup Snapshots\<date and time>yourself.) - Find the files or folders you need.
- Copy them to where you want them, for example your Desktop or their original folder, and open the copies.
Don't open and edit files directly inside a snapshot folder, and don't move, rename or delete things in there. The next section explains why.
Please read this before relying on MyLocalBackup.
- Snapshots share unchanged files. A file that didn't change between backups is stored once and appears in every snapshot through NTFS hard links. That's what keeps the backup small, but it also means that editing a file inside a snapshot changes it in every snapshot that shares it. Treat snapshot folders as read-only: copy files out first, then work on the copies.
- Low-space cleanup is on by default. When the destination drive has less than 20 GB free, each backup deletes the oldest snapshots (up to 10 per backup) until there's room again, always keeping the newest 5. On a nearly full drive with hourly backups, that can shrink your history to a few hours. You can turn this off in Settings > Automatically delete old backups if disk is full; then you'll have to free up space yourself. The normal thinning (one per day, then one per week) always runs.
- No shadow copies (VSS). Files that another program has locked are skipped and listed under Settings > Skipped Files. Files that are being written while the backup runs (open databases, mail stores, virtual machine disks) can be copied in a half-written state. Close those programs before a backup when you need a clean copy.
- Folder links aren't followed. Symbolic links and junctions inside your source folders are saved as links (this needs Windows Developer Mode) or listed under Skipped Files. The files they point to are only backed up if that folder is also one of your sources.
- Keep the backup somewhere else. Pick a destination outside your source folders, ideally on a separate drive. A backup on the same disk as the originals won't help if that disk fails.
- Check the log now and then. If a source folder is missing (for example on an unplugged drive) or a folder can't be read, it's skipped with a note in the activity log, and the backup still shows as completed.
Both are fixed in 0.9.17.
- Deleting a snapshot could delete real files outside the backup (v0.7.5 to v0.9.16). Windows puts folder links such as
My MusicandMy Picturesinside Documents, and the app saved them into snapshots as links (with Developer Mode on, or when run as administrator). If a snapshot delete was cut short (app closed, PC shut down) and finished later, it followed those links and deleted the files in the real folders they point to. - Resuming an interrupted backup could overwrite older versions (v0.8.5 to v0.9.16). When a file changed before a backup resumed, the new version was written through the hard link that the file shared with older snapshots, so those snapshots silently got the new version too.
If you used an affected version: update, and check that the folders your Documents links point to (Music, Pictures, Videos) still hold your files.
MyLocalBackup is provided as is, without warranty of any kind, under the MIT License. In no event are the authors liable for any claim, damages or other liability, including loss of data. It's a free tool, not a guarantee.
By installing or using it you accept that you use it entirely at your own risk and that you alone are responsible for choosing the right source and destination folders, for keeping a second backup of anything you can't afford to lose (another drive, or an off-site or cloud copy), and for checking every so often that you can actually open files from a snapshot. The full terms are in DISCLAIMER.md.
- Framework: .NET 9 / WPF (Windows)
- Database: SQLite via
Microsoft.Data.Sqlite(WAL mode on local drives, exclusive mode on removable) - Installer: WiX v5 Burn bundle EXE wrapping MSI (per-user install to
%LOCALAPPDATA%\Programs\MyLocalBackup— no admin required) - Self-contained: Bundles the .NET runtime — no separate .NET install required
- Windows 10 or 11 (64-bit)
- NTFS destination drive (hard links require NTFS)
dotnet build MyLocalBackup.UI/MyLocalBackup.UI.csproj
Data-safety tests (they work in a throwaway folder under %TEMP% and never touch your real backups):
dotnet run -c Release --project tests/MyLocalBackup.SafetyTests
Unit tests for the next-generation storage engine (work in progress, see below; also sandboxed under %TEMP%):
dotnet test MyLocalBackup.Core.Tests
MyLocalBackup.Core/Storage/ also contains the first pieces of a planned 1.0 storage engine: a store that keeps each file's content once under its SHA-256 hash and checks it before accepting it, a per-snapshot SQLite manifest, and a repository manager that only publishes a snapshot after its manifest verifies. The app does not use this code yet, so it changes nothing about how backups work today. The design and plan are in docs/superpowers/.
powershell -ExecutionPolicy Bypass -File release-build.ps1 -Version X.Y.Z
The script handles: publish, regenerate Files.wxs, MSI build, Burn bundle EXE build, and copy the installer to Desktop. Hashes are printed for release verification.
MyLocalBackup.Core/ Backup engine, database, configuration, models
MyLocalBackup.UI/ WPF desktop application
MyLocalBackup.Core.Tests/ Unit tests for the v1 storage engine (work in progress)
tests/ Data-safety regression tests
docs/superpowers/ Design and implementation plan for the v1 storage engine
Staging/ WiX MSI + Burn bundle EXE packaging
release-build.ps1 Automated release build script
PackagePortable.ps1 Portable ZIP packaging script
MyLocalBackup is open source under the MIT License.
You may use, copy, modify, merge, publish, distribute, sublicense, and sell copies of the software, provided the MIT copyright and permission notice are included in copies or substantial portions of the software.
Third-party dependencies and build tools remain under their own licenses. In particular, WiX Toolset extensions are external build dependencies and are not vendored in this repository. The third-party components shipped in the installers (the .NET runtime, Microsoft.Data.Sqlite, SQLitePCLRaw/SQLite, H.NotifyIcon and the WiX runtime) are listed in THIRD-PARTY-NOTICES.md, which is installed next to the app.