One of the things that makes Obsidian so magnetic is its local-first philosophy: every note lives on your own machine as a plain Markdown (.md) file. You own your data completely, and you can access everything even when the internet goes dark.
But the moment you want to jot down a thought or review notes on your phone (Android/iOS) or a second computer, things get complicated. Sure, Obsidian offers Obsidian Sync, but it comes with a hefty monthly fee. And leaning on public cloud services like Google Drive, OneDrive, or iCloud often means slow syncs, constant file conflicts, or — worse — the nagging worry that your deeply personal Second Brain is sitting on someone else's servers.
If you're looking for a sync solution that fully honors privacy-centric principles and data sovereignty, the best option right now is Syncthing — a peer-to-peer file sync tool that connects your devices directly. No cloud. No middleman. Free and as secure as it gets.
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### What Is Syncthing, and Why Is It Perfect for Obsidian?
Syncthing is an open-source, real-time file synchronization tool that exchanges files directly between your devices over your network — no third-party server in the loop.
Here's why Syncthing is a natural fit for your Obsidian vault:
1. Maximum security with encryption: All data is transmitted over TLS with end-to-end encryption, so no external device can intercept your notes.
2. No cloud storage required: Files sync directly from your computer to your phone — nothing ever touches the internet.
3. Free and unlimited: No storage caps beyond what's on your own devices, and zero monthly fees.
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### Installation & Device Pairing
To keep things concrete, let's walk through syncing between a computer (Windows/macOS/Linux) and an Android phone. (For iOS, due to sandboxing restrictions, I'd recommend alternatives like Mobius Sync or Obsidian Git instead.)
#### 1. Install Syncthing on Your Computer
* Download and install Syncthing from the official website, or on Linux/macOS, install it via your package manager.
* When you launch Syncthing, it opens a web-based control panel at http://127.0.0.1:8384.
* Give your device a clear name, e.g., "My-Desktop-PC."
#### 2. Install Syncthing on Your Android Phone
* Download the Syncthing app from the Google Play Store.
* Open the app and grant it storage access and battery optimization exemption (so Syncthing can run in the background without the OS killing it).
#### 3. Pair Your Computer and Phone
* On your computer, click Actions → Show ID to display the QR code and device ID.
* On your Android phone, open the Syncthing app, go to the Devices tab, tap the + button, then tap the camera icon to scan the QR code on your computer screen.
* Name the phone device, then tap Save.
* Back on your computer, a green notification will pop up asking if you want to connect with the new device. Click Add Device to accept.
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### Sharing Your Obsidian Vault & Syncing Notes
Now that both devices are paired, it's time to share the folder where your notes live.
#### 1. Start Sharing from Your Computer
* In the browser control panel, click Add Folder.
* Folder Label: Give it a name, e.g., "Obsidian-Vault."
* Folder Path: Point it to your Obsidian vault directory (e.g., /home/linn/documents/MySecondBrain).
* Switch to the Sharing tab and check the box next to your phone's name to indicate you want to share this folder with it.
* Click Save.
#### 2. Accept the Folder on Your Phone
* The Syncthing app on your phone will show a notification that your computer wants to share a folder. Tap it.
* Choose the destination folder on your phone where you want the notes to live. I recommend creating a fresh, dedicated folder (e.g., in your phone's Documents directory).
* Make sure the folder type is set to Send & Receive so you can edit and sync in both directions. Then tap Save.
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### Pro Tips: Handling File Conflicts & Junk Files
Frequently edited notes can trigger file conflicts or data overwrites — especially with Obsidian's internal config files. Here's how to keep things clean:
#### 1. Excluding Specific Files with .stignore
Obsidian stores files like .obsidian/workspace.json and workspace-mobile.json that track your last-opened screen state per device. If these sync to your phone, they'll immediately conflict with the phone's own workspace state, triggering endless conflict alerts.
Create a file named .stignore in the root of your Obsidian vault (on your computer) and add these lines:
.obsidian/workspace.json
.obsidian/workspace-mobile.json
.stversions
Syncthing will automatically skip these files, making your sync experience noticeably smoother.
#### 2. Enabling File Versioning
To protect against accidental overwrites or deletions, enable File Versioning in Syncthing's control panel:
* Edit the shared folder in Syncthing and go to the File Versioning tab.
* Choose Simple File Versioning or Staggered File Versioning.
* Syncthing will create a hidden .stversions folder that archives previous file versions, so you can always recover a note if something goes wrong.
#### 3. Battery & Wi-Fi-Only Sync Settings
In the mobile app, you can configure sync conditions to reduce heat and save battery. Set Syncthing to sync only when connected to Wi-Fi, or only while the phone is charging. This gives you great flexibility in your daily workflow.
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### The Joy of 100% Offline Note-Taking
Syncing your Obsidian vault with Syncthing truly breaks free from the limitations of traditional note-taking. You can open Obsidian on your phone the moment a great idea strikes while you're on the go, jot it down, and pocket your phone. Walk back to your desk, and that note is already sitting there, fully rendered on your computer screen — no action required on your part.
And perhaps most importantly, there's a deep sense of peace knowing that your data, memories, and creative ideas travel through a private network known only to your own devices. No big tech company is harvesting your personal information. This is what a true Second Brain & PKM workflow in the modern era looks like.