It can feel like cloud storage is the only way to operate, especially with the limitation on a local drive. It's especially frustrating when you realize your phone and laptop are already out of sync. The problem isn't the cloud itself, although it is hard to trust. The problem is that nothing fills the gap once you leave it. Syncthing does. It runs on your devices, talks directly between them over your local network, and never touches a third-party server. You don't have to worry about an account, fee, or any company holding copies of your files.
How to get Syncthing running and pair your devices
You just need two devices that learn to trust each other directly
You can start by downloading and installing Syncthing on both your computer and your phone. Since it's open-source and decentralized, you won't be creating an account, signing in, or paying a subscription. All you're going to do is run software, which makes it better than SMB.
It works on Windows, macOS, Linux, FreeBSD, and Android. On your computer, grab the latest release for your operating system, unpack it, and run the executable. On your phone, find it in your app store, where you may also find community builds tailored to specific devices.
The first time you launch Syncthing on your computer, it generates a configuration file and your personal encryption keys. Then it opens its admin interface in your browser.
The layout is straightforward. On the left, you'll see your folders, but at first, it will just be a default one in your home directory, named "Unshared" until you connect to something. On the right is Remote Devices, which, for now, just shows your own machine.
To connect your phone, the two devices need to swap a Device ID. This is a 56-character string that's unique to each installation. Don't worry because you don't have to memorize it. Just click Actions at the top right and choose Show ID.
That gives you the string and a QR code. Open Syncthing on your phone, go to add a new device, and scan the code with your camera. You can also do it the other way around, but this is easier this way.
Either way, once the ID is entered, you pick which folders to share, and a moment later, the other device gets a prompt asking you to confirm the connection. Accept it, and the two are linked.
If you want to keep everything strictly on your local network, go into the connection settings and turn off Global Discovery and Enable Relaying. With those off, the software falls back to Local Discovery, which finds your devices on the local network instead of reaching out to the internet.
You have to make sure you don't delete everything
Once sync is live, a stray delete on one device hits every device
Once your devices are restricted to the local network, the next step is pairing them and choosing which folders you want to keep in sync. On the computer, click the option to add a new folder, and you'll be asked to give it a label, set the local path on your hard drive, and assign it a Folder ID. That ID is important because it has to match every device you want to include, or the sync won't work.
After you add the folder and select your phone as a sharing target, a prompt will pop up on your phone asking you to accept the folder and pick where it should live in local storage. The moment you approve it, the two devices compare what they each have and start syncing directly, transferring files in encrypted chunks without any cloud service in the middle.
That all sounds really simple, but you still have to be careful. Changes and deletions happen across all your devices. Basically, if you accidentally delete something on one machine, it will wipe it everywhere else just as fast.
Before you use it in earnest, make sure you protect yourself from that. You'll want to turn on file versioning. In the folder's advanced settings, there's a File Versioning dropdown that, when enabled, quietly saves a copy of any file just before it gets overwritten or deleted, tucking those older versions into a hidden folder called .stversions.
There are a few strategies to pick from, depending on how much coverage you want and how much space you're willing to take up.
Trash Can versioning keeps the most recent deleted copy of each file, which is good if you're only worried about accidental deletions. Simple versioning lets you set a number, like the last five versions before dropping the oldest. This can add up, and I'd say only keep two if you try this.
Staggered versioning is the most thorough option if that's what you need. It automatically saves hourly, daily, weekly, and monthly snapshots and thins them out over time to keep your disk from filling up. If you're writing a movie or making a game, this may be your best bet.
You can replace cloud backup without trusting anyone else's hardware
You don't have to give away all your data to be safety
Most people would rather pay for the service because all this sounds too easy. This gives you privacy and no monthly fees, but it isn't as perfect as it sounds. Paid services tend to give you a web dashboard that you won't get here.
You can't just browse your files from any browser, and more importantly, you lose the automatic off-site redundancy that keeps your data safe if something catastrophic happens to your house. So a fire, flood, or anything like that is a real danger. When your files only live on hardware you physically own, one bad event or a theft could wipe everything out at once.
The good news is you can solve this for free with spare hardware you probably already have sitting around. An old laptop you're not using, a Raspberry Pi, or even a cheap external drive you can hide away will work. This can be your version of a backup.
All you have to do is designate the remote machine as an untrusted node and set the shared folder to Receive Encrypted. From that point on, your primary machine scrambles everything locally. The remote device is just there to receive and store the files in unreadable noise. If that hardware is ever stolen or seized, whoever has it gets nothing useful without your folder password.
If disaster does hit your house, you pull the encrypted data back down, restore it to a new machine with your original identity, and you're back.
Syncthing is a lot better than other options
Cutting out cloud storage means accepting that the safety net is now yours to manage. While it needs spare hardware and a willingness to set it up, it's pretty easy. Once you've got Syncthing up and running, the ongoing cost is just what you spend on electricity. It's definitely worth the time and effort.
