Free Software Collection
Free Backup and Sync Software
Sync and backup are different things. Sync keeps files identical across devices, so when a file is deleted by mistake or encrypted by ransomware, that result is synced to every device too. Backup keeps a copy from a point in time you can return to after something goes wrong. The usual rule is 3-2-1: three copies, on two kinds of media, with one offsite. The offsite copy is usually a cloud, and it should be encrypted on your machine before upload so the key stays with you and the provider holds only ciphertext. The list follows those steps: Kopia for scheduled incremental backup, Syncthing and Nextcloud for sync, rclone for moving data to any cloud storage, Cryptomator and VeraCrypt for encryption, and Immich and Ente Photos for phone photos.
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Selection Criteria
- You choose where data lives: a local disk, a NAS, your own server or any cloud storage.
- Encryption on your own machine, so providers and relays never see plaintext.
- No subscription by capacity or device count, and no feature limits on self-hosted versions.
- Open source, with data that can be restored without the original vendor's service.
Recommended Tools
Kopia
Encrypted, deduplicated incremental backup — you choose where it lands
- Open Source
- No Ads
- No Tracking
- No Sign-up
Syncthing
Peer-to-peer real-time file sync, no cloud needed
- Open Source
- No Ads
- No Tracking
- Offline
rclone
Seventy-plus cloud storage services, one set of commands
- Open Source
- No Ads
- No Tracking
- No Sign-up
Cryptomator
Encrypt files before they hit the cloud — the key stays with you
- Open Source
- No Ads
- No Tracking
- No Sign-up
VeraCrypt
Open-source disk encryption that locks down drives and USB sticks
- Open Source
- No Ads
- No Tracking
- Offline
Nextcloud
Everything a cloud drive does, on a disk you own
- Open Source
- No Ads
- No Tracking
- Cross-platform
Immich
Google Photos on your own disk, with your disk as the storage limit
- Open Source
- No Ads
- No Tracking
- Cross-platform
Ente Photos
An end-to-end encrypted photo library where the server only ever holds ciphertext
- Open Source
- No Ads
- No Tracking
- Cross-platform
FAQ
- I already sync to a cloud drive. Do I still need backup?
- Yes. Sync carries accidental deletions and ransomware-encrypted files along with everything else. Each Kopia backup is a full snapshot you can restore from, only changed blocks are transferred, and retention policies can keep, say, one copy a day for 7 days and one a month for 12 months. Set up a daily scheduled task, then restore a few files right away to confirm the process works.
- Syncthing or Nextcloud?
- To keep files in step across your own devices, Syncthing: direct peer-to-peer, no central server, no extra machine to maintain. For share links, calendar, contacts and in-browser previews too, Nextcloud — it needs an always-on machine, and updates, backups and HTTPS certificates are your job. Both are sync tools and neither replaces a backup tool like Kopia.
- How do I keep a commercial cloud provider from reading my files?
- Encrypt before upload. Cryptomator creates a vault inside the sync folder and encrypts file contents and names with AES-256, while the provider's own client syncs as usual. rclone's crypt backend does the same for people moving data in bulk from the command line. Kopia encrypts before upload when it backs up to a cloud. VeraCrypt suits encrypting a whole external drive or USB stick — the offline copy in a 3-2-1 setup. With all of these, a lost password means unrecoverable data, so store it separately.
- Immich or Ente Photos for phone photos?
- With a server of your own, Immich: the phone app uploads originals automatically, and face recognition and image search run on your machine; start with at least 4 GB of RAM. Without a server to maintain, Ente Photos: photos are encrypted on the phone before upload, the hosted service has a permanent 10 GB free tier, and the server can be self-hosted. Either counts as one copy — photos still need another offsite or offline backup.