Syncthing: Sync your data across devices differently

Every month, millions of us blindly pay a "data tax" to Apple, Google, or Microsoft just to access our own files.

We accept arbitrary storage limits, rising monthly subscription fees, and the unsettling reality that our personal photos, tax documents, and project files are sitting on a server controlled by a massive corporation—and regularly scanned by their algorithms.

I used to be part of that cycle, then I decided to take my data back.

Then, I set up Syncthing on a Synology NAS, turning my own hardware into a private, hyper-fast, zero-cost cloud. From my own experience, I can tell you that ditching Big Tech for a self-hosted sync solution isn't just about privacy—it is fundamentally a better, faster way to work.

Here is exactly how I use it, and why I’ll never go back to renting cloud storage.

The Setup: How the "Anti-Cloud" Actually Works

Most cloud services are centralized: your phone uploads a file to a Google server in California, and your laptop downloads it from that same server. It’s inefficient and slow.

Syncthing takes a completely different approach. It is an open-source, peer-to-peer (P2P) continuous file synchronization tool. It syncs files directly between your devices using end-to-end encryption. No central server required.

But what if my laptop is turned off when I want to sync something from my phone? That’s where the Synology NAS comes in. By installing Syncthing on my local server, I created an "always-on" master node.

Now, my NAS, my Linux machine, my Android phone, and my remote Debian servers are all part of a private mesh network. They talk to each other constantly, seamlessly keeping everything perfectly in sync.

Here is what that actually looks like in practice, with the numbers to back it up:

1. Blistering Local Speeds (120 MB/s vs. ISP Bottlenecks)

When I dump 10 GB of video files or a heavy project folder from my MacBook into a synced folder, it doesn't upload to the internet. Because my MacBook and my Synology NAS are on the same local network, Syncthing recognizes this and routes the traffic locally.

Files appear on my NAS and other local devices almost instantly. There is no waiting for a cloud provider's progress bar. It happens at bare-metal network speeds.

2. Zero Monthly Subscriptions ($0 vs. $120+/Year)

Renting 2TB of storage from Google One or Apple iCloud costs about $9.99 a month. That’s $120 a year, forever. Need more space? The price jumps drastically.

Because my Synology NAS has dual 8TB drives in it, I effectively have an 8-Terabyte private cloud. It handles my backups, my Obsidian notes, my code repositories, and my photo libraries without ever asking for a credit card. The hardware pays for itself in avoided subscription fees.

3. Absolute Cross-Platform Freedom

Apple wants you locked into iCloud. Microsoft wants you glued to OneDrive. If you use a MacBook for work, a different Apple ID on your personal iPhone, and a Debian server for hosting apps, getting files between them natively is a nightmare of conflicting accounts and permissions.

Syncthing doesn't care who made your hardware or what account you are logged into.

I can drop a file into a folder on my Mac, and it immediately appears on my remote Debian server and my personal iPhone. You authenticate devices by exchanging a unique ID string, not by signing into a corporate ecosystem. This completely removes the friction of managing different Apple IDs or Google accounts across your work and personal devices.

4. True Digital Sovereignty and Privacy

When you upload your data to a commercial cloud, it is usually encrypted in transit, but the provider holds the encryption keys on their servers. They can (and do) scan your files for compliance, advertising profiles, or AI training data.

With Syncthing, your data is yours. The connection between my devices is secured using TLS with perfect forward secrecy. But more importantly, the files physically reside on hard drives sitting in my house. No corporation has access to them. No algorithm is scanning them. If my internet goes completely offline, my local devices continue to sync with the NAS flawlessly.

Taking control of your data isn't just for system administrators. Setting up a Synology NAS and installing the Syncthing package takes about 15 minutes.

Once it’s running, it fades completely into the background. Files just magically appear where they are supposed to, instantly, securely, and for free.

Self-hosting is about rejecting the default. It’s about realizing that you don't need to rent a server in a massive data center just to sync a text file between your phone and your laptop. You have the hardware. It’s time you owned the data, too.

• Syncthing Official Website: Download the core software for Mac, Windows, and Linux.
• SynoCommunity: The easiest way to install Syncthing directly on your Synology NAS (no Docker required). Just add their repository to your Synology Package Center.
• Mobius Sync: The best third-party Syncthing client for iOS and iPadOS.
• Syncthing on Android: The official Android client available via Google Play (and F-Droid).