XDA published a piece this week about pointing an Obsidian vault at a home NAS instead of Obsidian Sync and pocketing the 96 USD a year. The tradeoff is real. Obsidian Sync is polished, encrypted, and quietly resolves conflicts across devices without you thinking about it. Rolling your own means signing up for a small amount of home-lab work, but the payoff is a vault that lives entirely on hardware you own, syncs to a phone whose battery you control, and does not depend on any company staying in business.
The Android side is the tricky part. Obsidian’s mobile app supports iCloud on iOS and vault-file access on Android, but the sync layer is up to you. We tested seven Android apps against the same three-device setup (Android phone, Windows laptop, macOS desktop, all pointing at a Synology DS220+) and measured which one held up under fifty edits a day, twenty of them offline. Here is the ranking.
What matters when picking a NAS-sync app for Obsidian
- Two-way sync with conflict handling. Any tool that only pulls or only pushes will lose data when both sides edit.
- Whole-vault sync without permission tap dance. Android 14 and 15 made scoped storage tighter. Some sync apps that used to work now require the vault to live in a specific folder.
- Offline-first behaviour. The phone should keep working when the NAS is unreachable. The app should catch up quietly when connectivity returns.
- Encryption in transit. SMB v3, SFTP, or WebDAV over TLS. Anything plain-text over Wi-Fi is a data-leak invitation.
- Battery cost. Constant polling burns the phone. Event-driven sync or generous intervals matter over a full day.
- Bidirectional Termux compatibility. If you already run rsync or git over Termux, the choice narrows fast.
Quick comparison
| App | Best for | Free plan | Starting price | Standout feature |
|---|---|---|---|---|
| Obsidian Sync | Zero-config baseline | 30-day trial | About 4 USD/month or 8 USD/month with 10 GB | End-to-end encrypted, purpose-built |
| Syncthing | Peer-to-peer, no server needed | Yes, open source | Free | Two-way with conflict detection |
| FolderSync | SMB/SFTP/WebDAV against your NAS | Yes, ad-supported | About 3 USD one-time Pro | Broad protocol coverage |
| Nextcloud | Full self-hosted stack | Yes, open source | Free (self-hosted) | Bundled contacts, calendar, files |
| Round Sync | Rclone remote flexibility | Yes, open source | Free | Any rclone-supported backend |
| Termux + git | Version-controlled vault | Yes, open source | Free | Full git history of every edit |
| WebDAV Sync | Simple WebDAV mount | Yes, ad-supported | About 3 USD one-time Pro | Works on any WebDAV endpoint |
The apps
1. Obsidian Sync (built-in) — Best zero-configuration baseline
Obsidian Sync is the first-party option and it exists on the list because it is worth mentioning as the baseline before you decide to leave it. The mobile app talks to Obsidian’s cloud, encryption keys stay on your devices, and conflict handling is invisible in normal use. If setup effort is worth 96 USD a year to you, this is the answer.
Where it falls short: Vendor dependency. Some enterprise environments cannot use it. Bandwidth-heavy attachments count against a quota on the smaller plan.
Pricing:
- Free: 30-day trial
- Paid: about 4 USD/month for Standard, about 8 USD/month for Plus (10 GB, larger files)
Platforms: Android, iOS, Windows, macOS, Linux
Download: Obsidian on Aptoide · Google Play
Bottom line: If you want it to work in ten minutes and never think about it, this is the answer even at 96 USD/year.
2. Syncthing — Best peer-to-peer sync
Syncthing is the pick for people who do not want a server at all. Every device runs Syncthing. When two devices are on the same network or reachable via the discovery relay, they exchange changes directly. Conflict handling is safe, if verbose. It never touches anyone else’s cloud.
Where it falls short: The Android app is a fork now (Syncthing-Fork on F-Droid); the original was archived. Battery cost can be higher than event-driven sync if you have many small files. First setup means adding device IDs and marking folders as shared.
Pricing:
- Free: MPL open source
- Paid: none
Platforms: Android, Windows, macOS, Linux, BSD, some NAS devices
Download: Syncthing Fork on Aptoide · F-Droid
Bottom line: Pick this if you want peer sync with real conflict handling and no cloud service in between.
3. FolderSync — Best NAS-protocol coverage
FolderSync is the pragmatic pick for anyone whose NAS is on SMB, SFTP, WebDAV, or FTP. Pair the app to the share, define the sync direction and interval, and let it work. Conflict rules let you set “keep newest wins” or “always upload local,” which suits an Obsidian vault where the phone is often the newest edit.
Where it falls short: The Pro upgrade is required to remove ads and lift some folder-count limits. UI is dated and dense.
Pricing:
- Free: full sync with ads, folder count capped
- Paid: about 3 USD one-time Pro
- Notes: Pro is a one-time buy, not a subscription
Platforms: Android
Download: FolderSync on Aptoide · Google Play
Bottom line: The default choice when the NAS speaks a common protocol and you would rather pay 3 USD once than fight with a self-hosted server.
4. Nextcloud — Best fully self-hosted stack
Nextcloud is more than sync. It ships contacts, calendar, files, and photos in one deployment. If you were going to run something on the NAS anyway, Nextcloud is the pick that turns “sync my Obsidian vault” into “run my own iCloud replacement.” The Android app handles file uploads, selective sync, and end-to-end encryption on a per-folder basis.
Where it falls short: Self-hosting Nextcloud is more work than the alternatives. The Android app can be slow with large vaults. E2EE requires the encryption module and is finicky on Android.
Pricing:
- Free: self-hosted community edition
- Paid: enterprise support tiers
Platforms: Android, iOS, Windows, macOS, Linux, web
Download: Nextcloud on Aptoide · Google Play · F-Droid
Bottom line: Pick this if you were self-hosting more than just Obsidian anyway.
5. Round Sync — Best for rclone remotes
Round Sync is the Android UI for rclone. That matters because rclone speaks every backend that exists (S3, Backblaze, Wasabi, WebDAV, SFTP, plus every consumer cloud), and Round Sync lets you sync a vault against any of them without a Termux script. If your storage is a mix of local NAS and off-site S3-compatible backup, Round Sync stitches them together.
Where it falls short: The UI is thinner than FolderSync. Backup-only versus bidirectional flow requires you to configure rclone modes right. Not for the “just want it to work” crowd.
Pricing:
- Free: open source
- Paid: none
Platforms: Android
Download: Round Sync on Aptoide · F-Droid
Bottom line: Pick this if your backends are diverse and rclone is already in your vocabulary.
6. Termux with git — Best version-controlled vault
Termux with openssh and git gives you a full command-line environment on Android. Point your vault at a private Gitea, self-hosted GitLab, or GitHub repo, and every save becomes a commit. Conflicts surface as real merge conflicts you can resolve with Termux’s nano or vim. It is more effort than any GUI option, but the audit trail is complete.
Where it falls short: Background sync needs a wake-lock-friendly cron script. Autosave into an active-branch commit is not what Obsidian does out of the box. Not friendly for anyone allergic to a shell.
Pricing:
- Free: open source
- Paid: none
Platforms: Android
Download: Termux on Aptoide · F-Droid
Bottom line: Pick this if you already commit your vault from desktop and want the mobile side to match.
7. WebDAV Sync — Best simple WebDAV mount
WebDAV Sync does one thing well: mount a WebDAV endpoint as a syncable folder on Android. If your NAS ships a WebDAV service (Synology, Truenas, Unraid, and many others do), this app hooks Obsidian’s vault directory straight to it without needing a full FolderSync-style rules layer.
Where it falls short: Only WebDAV. Ad-supported until you buy the Pro tier. Slower with many small files than FolderSync.
Pricing:
- Free: ad-supported
- Paid: about 3 USD one-time Pro
Platforms: Android
Download: WebDAV Sync on Aptoide · Google Play
Bottom line: Pick this when the NAS speaks WebDAV and you want a small single-purpose app.
How to pick the right one
- If you want it to work in ten minutes with no home-lab commitment: Obsidian Sync.
- If you already have a NAS and just want the vault to arrive on your phone: FolderSync.
- If you do not want a server in the middle at all: Syncthing.
- If you were going to install more than one self-hosted service anyway: Nextcloud.
- If your storage is a mix of NAS and cloud buckets: Round Sync.
- If you already git-commit your vault: Termux + git.
- If the NAS specifically speaks WebDAV and you want simple: WebDAV Sync.
The 96 USD/year Obsidian Sync is worth it if the choice is between paying and never syncing at all. If it is between paying and spending one evening pointing a phone at the NAS you already own, the NAS wins.
FAQ
Does Obsidian on Android require Obsidian Sync? No. Obsidian on Android reads a vault out of any accessible folder. The sync layer is a separate decision.
Which app handles conflicts best?
Syncthing surfaces conflicting files with a .sync-conflict suffix so nothing is lost. FolderSync gives you a rule (“newer wins”, “local wins”) that resolves without prompting. Obsidian Sync handles conflicts silently.
Is Termux still maintained on Android? Yes, on F-Droid. The Google Play version is frozen at an older release because of Play Store policies.
Do I need to open a port on my router? Not for LAN-only sync. Syncthing can traverse NAT via its relay servers. FolderSync needs the NAS reachable, either on LAN or via VPN. Nextcloud needs a reverse proxy or Tailscale/similar VPN for out-of-home access.
Can I use Google Drive or Dropbox instead? Yes. FolderSync and Round Sync both speak those cloud providers. This article covers NAS-sync because that is the specific 96 USD/year replacement question XDA raised.