I keep my Obsidian notes synced with AutoSync and Google Drive. However, it’s not ideal for sharing large files due to the limited storage offered by Google and the slow sync speed. Since I only needed to sync files locally, I decided to give peer-to-peer syncing a chance with SyncThing.

SyncThing is an open-source peer-to-peer (P2P) file synchronization service that can transfer files faster than any cloud storage, along with greater flexibility and control over what you share. However, SyncThing is not the most intuitive program to set up, but once you are past that hurdle, it just works.

Setting up SyncThing

Getting the right apps and connecting your devices

SyncThing lets you build your own sync system. It creates direct connections between your devices over a local network, transferring data peer-to-peer instead of routing it through third-party servers. This approach has two benefits: faster transfer speeds since your files move directly between devices, and enhanced privacy because your data never leaves your control.

However, the bigger issue with SyncThing is the setup. The developer has discontinued the official Android app, and the Windows app is anything but functioning. When I installed the Windows app, it added two shortcuts for starting and ending the service. Whenever I tried to launch it, it ended with an error, and the configuration page that was supposed to open a web interface returned blank pages.

After some digging, I found several maintained SyncThing forks that work. For Windows, you can use SyncTrayzor v2. Even though Edge flagged it as a “not usually downloaded app,” I ran it through VirusTotal, and it came out clean. On my Android phone, I installed SyncThing Fork. For Mac, you can try SyncThing-macOS, and Mobius Sync for iOS (it’s a paid app).

SyncThing-Fork

OS nel0x

Platform Android

Syncthing-Fork is an Android wrapper for Syncthing, enabling secure, decentralized file synchronization between devices without any cloud services. Provides UI enhancements, battery optimizations, and advanced sync control

Once you’ve installed the apps on both devices, you need to connect them. The GUI authentication notification asking you to set a username and password is only necessary if you have a shared PC and fear someone accessing your files without your permission. If not, you can leave it as a default.

Open SyncThing on both of your devices, then click Add Remote Device. Click the Device ID drop-down and choose another device from the list. You’ll only see another device’s ID and not the name. Enter a name for the device and click Save to accept the connection request that pops up on another device, and your devices are now paired.

If you are pairing over the internet, you’ll need to manually add the device ID from your phone to the PC or vice versa and then accept the connection.

Creating your SyncThing folder pairs (choose what data to sync)

Selecting and configuring which folders to keep in sync

With the devices connected, the next step is choosing what to sync. SyncThing lets you sync any folder on your device and configure versioning and monitoring settings.

On your computer, click Add Folder in SyncThing. Give it a label you’ll recognize (like Project Images) or leave it blank. Leave the ID as default, and then choose the folder path on your computer that you want to sync.

In the Sharing tab, select the device that should receive this folder. You can even set different sync types—maybe you want your phone to only receive files but not send changes back. Perfect for reference materials you don’t want accidentally edited on mobile.

On your other device, accept the folder invitation that appears on your device’s notification panel. Then, type a name for the folder label, and choose where to store those files locally. Finally, let SyncThing do its initial sync. This might take more than a few minutes, depending on folder size.

You can create multiple folder pairs with different rules or edit existing ones to reconfigure them. I sync my current projects folder both ways between devices, but my archive folder is send-only from my PC to free up phone storage while keeping files accessible.

SyncThing is fast, secure, and offers complete control

The technical advantages that make peer-to-peer syncing superior

When both devices are on your home Wi-Fi, files sync at a reasonable speed. Syncing can feel a bit slower if you are working with tons of individual files like images, documents, and screenshots, but after the initial sync, it’s a breeze. I mainly use it to sync my project images and videos, so that I can keep my phone gallery tidy.

Another underrated aspect of SyncThing is secure file transfer. All connections use TLS encryption, and devices authenticate each other using unique IDs, so unauthorized devices can’t connect even if they’re on your network. You can even add passwords to individual folders for extra protection. Also, since there is no central server, there is nothing to get hacked and expose your files.

SyncThing also offers granular control over what files are synced. You can exclude certain file types, set bandwidth limits, and configure versioning to keep old copies of changed files. SyncThing even handles conflicts intelligently. For example, if you edit the same file on two devices, it’ll keep both versions and let you sort it out rather than randomly picking one.

SyncThing is useful even if you use cloud storage

SyncThing can work alongside free-tier cloud services if you still use them. Whether you want to share sensitive documents that you can’t risk uploading to third-party servers or need faster syncing across devices on your local network, SyncThing gives you the flexibility that cloud storage alone can’t provide.

That said, SyncThing is just a sync utility, not a backup solution. When you delete a file on one device, it vanishes from all synced devices (unless you’ve configured one-way sync). A reliable data backup strategy would involve using a dedicated backup tool like Duplicati to create complete file backups to the cloud or local storage.

Despite having little to no official support, SyncThing works incredibly well. Once you get through the somewhat unconventional initial setup, you’ll have a reliable sync solution that works across your devices and offers unmatched control over your data.