Get your LAN sycn groove on with Synthing + Localsend!

If you work in a small office, run a home business, or just have a bunch of devices around the house, you've probably done this:

Emailed a file to yourself.
Uploaded something to Google Drive just to download it on the computer right next to you.
Had AirDrop envy because not everyone's on Apple.

Good news: your local network can do a lot of heavy lifting for you — no cloud required, no USB stick shuffling, no “what’s your email again?”.

In this post we’ll look at two brilliant (and free) tools for sharing files on your local area network (LAN):

LocalSend – perfect for quick, one-off transfers between nearby devices.
Syncthing – better for ongoing, automatic syncing between folders on multiple devices.

By the end you'll know when to use each, and why you might want both. Say goodbye to cloud share links, logins and AI scanning your internal documents.

On site, I use LocalSend to move inspection photos from my phone to the laptop, and Syncthing to keep checklists and drawings in step across devices.

LocalSend: Share files to nearby devices

LocalSend is a free, open-source, cross-platform file sharing tool that allows you to share files to nearby devices.

Desktop and mobile device compatible - it just works the way it should. Support those who give or create value for you. Buy the Dev a coffee if you get value from this tool!

LocalSend: “AirDrop for everyone”

LocalSend is a free, open-source app that sends files and messages between nearby devices over your Wi-Fi or LAN, with no internet connection and no cloud.

Think of it as AirDrop, but it:

Works on Windows, macOS, Linux, Android and iOS
Doesn't care what ecosystem you're in
Uses end-to-end encryption, so only the sender and receiver can see the files

As long as devices are on the same local network (same Wi-Fi, same router), they can see each other and send files.

How LocalSend works (in normal-person terms)

LocalSend creates a secure, peer-to-peer connection between devices over your local network. There's no central server, and nothing goes off to a mystery cloud.

Roughly:

Each device runs the LocalSend app.
The app advertises itself on the LAN.
Other devices running LocalSend see you in the list.
You pick a device, send a file.
The other person taps Accept, and the file lands on their device.

Transfers are fast because they only travel over your LAN or Wi-Fi, not up to the internet and back.

Setting up LocalSend (step by step)

Here's the basic process for most offices or homes:

1. Install LocalSend

On phones/tablets:
- Open the App Store or Google Play and search for “LocalSend”.
On Windows/macOS/Linux:
- Head to the LocalSend website and download the version for your operating system.

Install it on every device you want to transfer files between.

2. Put all devices on the same network

Make sure everything is on the same Wi-Fi (or plugged into the same router/switch).
Guest networks can block devices from finding each other, so watch out for that.

3. Open LocalSend on each device

Each device shows a device name. Rename it to something sensible: "Tony-Laptop", "Office-PC", "Reception-iPad".
Leave the app open in the background on desktops.

4. Send a file

On the sending device:

Open LocalSend.
Tap Send (or the plus icon).
Select the file(s) you want to send.
Choose the device you want to send to from the list.

On the receiving device:

You’ll see a pop-up saying “[Device] wants to send you files”.
Tap Accept.
Choose where to save (depending on OS).

That's it. No logins, no accounts, no "verify your email".

When LocalSend is handy

LocalSend really shines for ad-hoc, one-off transfers, like:

Passing photos from your phone to the work PC.
Sending a large PDF to someone at the next desk.
Moving a video from a tablet to a laptop without filling up your cloud storage.
Quickly sharing files to a guest machine, without giving them access to your whole OneDrive or Google Drive.

If you just want to move a thing from this device to that device right now, LocalSend is your friend.

Syncthing

Synthing - securely share files on your LAN devices

Syncthing: your own private “always-on” file sync

Where LocalSend is about one-off transfers, Syncthing is about continuous syncing.

Syncthing is a free, open-source program that keeps folders in sync between two or more devices (laptops, desktops, servers, even phones) without a central cloud server.

You tell it:

“This folder on my laptop should match this folder on my office PC.”

...and it quietly keeps everything up to date in the background.

What devices does Syncthing run on?

Syncthing runs on:

Windows
macOS
Linux
Various BSD flavours
Android (via community apps)
iOS (via SyncTrain)

You can also run Syncthing on:

NAS boxes (e.g. a small home server or office NAS)
Cloud or VPS servers as a kind of “home base” (more on that below)

How Syncthing works

Under the hood, Syncthing:

Creates a unique device ID for each machine.
Lets you share folders between specific devices.
Uses encrypted, peer-to-peer connections to sync changes in real time or near real time.

There’s no central server you don’t control. You can use:

Just your LAN (everything stays inside your network), or
Your LAN plus the internet to sync with devices in other locations.

Setting up Syncthing on a simple LAN

A common small-office/home setup might be:

Laptop
Desktop PC
Maybe a NAS or always-on mini-PC

Let’s say we just want the laptop and desktop to share a “Projects” folder.

1. Install Syncthing

Go to the official site and download the installer for each OS.
Install it on both devices.

2. Start Syncthing & open the web UI

Run Syncthing. It opens a local web interface (usually at http://127.0.0.1:8384).
You’ll see two main areas: Devices and Folders.

3. Exchange device IDs

On each machine:

Click Actions → Show ID to see the device ID.
Copy the ID and add the other machine as a new device.

You’ll see a notification on the other machine asking to approve the connection.

4. Create a shared folder

On one device:

Click Add Folder.
Give it a name (e.g. “Projects”).
Choose the folder path on that machine.
Tick the other device under “Share with Devices”.
Save.

On the other device:

You'll get a prompt like "Device X wants to share folder 'Projects'. Accept?"
Choose where on that machine the folder should live, then approve.

Syncthing will then start syncing files between the two.

From now on:

Add a file to “Projects” on your laptop → it appears on your desktop.
Edit something on the desktop → the change is copied back to the laptop.

All over your LAN (or the internet, if you allow it), using encrypted connections and no third-party cloud.

When Syncthing is handy

Syncthing is great when you want ongoing, automatic syncing, for example:

A shared “Office Docs” folder across multiple PCs.
Keeping your home desktop and work laptop in sync.
Backing up key folders from each machine to a NAS or home server.
Keeping site photos, scans and drawings synced between machines without Google Drive or OneDrive.

If LocalSend is like passing someone a manila folder, Syncthing is like a shared filing cabinet that always has the latest version of everything.

Bringing Syncthing to iPhone

So far we've talked about Syncthing on laptops, desktops and a NAS. What about the same bring-your-own-cloud setup on your iPhone, iPad or Mac?

SyncTrain is a dedicated Syncthing app for iOS and macOS with a clean, easy interface.

What SyncTrain does

SyncTrain builds on Syncthing and adds mobile-friendly features:

Secure syncing with other Syncthing devices: your phone or Mac acts like any other Syncthing device.
Selective sync: pick specific files or subfolders instead of dumping a whole folder onto your phone.
On-demand access: browse a folder and download a file only when you need it.
Media streaming: stream audio and video from another device, handy if you keep big media libraries on a NAS or server.
iOS Files integration: synced folders appear in the Files app so you can open them in other apps.

An important note from the developer: like Syncthing itself, SyncTrain is not a backup tool. Delete a synced file on one device and it's deleted on the others. Keep proper backups elsewhere (I use BorgBase and Vorta; see Further Reading below).

Basic setup: adding your phone or Mac to your Syncthing network

The exact steps vary a little, but the flow is:

1. Install SyncTrain
On your iPhone, iPad or Mac, open the App Store, search for "SyncTrain" and install it like any other app.

2. Open the app and get the device ID
When you first open SyncTrain, it starts its own Syncthing instance and shows this device's name and ID, the same kind of ID you see in the standard Syncthing web interface.

3. Add your phone or Mac to another Syncthing device
On your desktop or laptop, open the Syncthing web interface. Add a new device, paste in the ID from SyncTrain, and give it a friendly name like Tony-iPhone. Then accept the connection prompt that appears in SyncTrain.

4. Share one or more folders
In Syncthing on your desktop, pick a folder (e.g. Projects or Photos-Archive) and tick your phone or Mac under "Share with devices". SyncTrain will ask where to store it and whether you want full or selective sync.

5. Choose how it behaves on mobile
For day-to-day use, turn on selective sync so only important files live on the phone, and use on-demand access to fetch the rest when needed. If you've got plenty of storage on an iPad or MacBook, you can fully sync certain folders.

LocalSend vs Syncthing: which should you use?

Short answer: they solve different problems, and you'll probably be happiest running both.

Here’s a quick comparison:

Use case	LocalSend	Syncthing
One-off file transfer	Excellent	Overkill
Continuous folder sync	Not designed for it	Excellent
Works fully offline on your LAN	Yes (localsend.org)	Yes (can be LAN-only) (Wikipedia)
Setup complexity	Very simple	A bit more setup, then mostly hands-off
Platforms	Win/macOS/Linux/Android/iOS (localsend.org)	Win/macOS/Linux/*BSD/Android/iOS (via apps) (Wikipedia)
Best for	“Send this file to that device right now”	“Keep these folders in sync across devices”

When you’d choose LocalSend

Use LocalSend when:

You're in the same room or office and just need to fling a file from one device to another.
You regularly move photos or videos from your phone to your PC.
You're working across platforms (say, an Android phone, Windows desktop and iPad) and want a simple way to move things between them, with no accounts and no cloud.

It's the digital equivalent of handing someone a USB stick, without the stick.

When you’d choose Syncthing

Use Syncthing when:

You want shared folders across devices that stay in sync automatically.
You’re sick of juggling which version of a file lives where.
You'd like a bring-your-own cloud for your home or office: your data, your hardware, no subscription.

For example, you could:

Run Syncthing on all your computers, plus a NAS or always-on mini-PC.
Use that always-on machine as your hub (it's still peer-to-peer, not a central cloud you don't control).

If you don't want to run a physical box, you can rent a small always-on virtual machine from a service like Shells.com (see link below) that you can reach from any device.

Install Syncthing on that VM and you've built your own cloud drive. It's still hosted by a provider, but you control the software and can encrypt the data, rather than relying on a big platform's sync service.

Why you might just set up both

Here's the sweet spot for most small offices and homes:

LocalSend for the quick, human stuff: "Can you send me that photo?", moving files off your phone after a site visit or inspection, and passing big files around without clogging the internet connection.

Syncthing for shared team folders on your LAN, keeping project files the same on your laptop and desktop, and quiet background copies to a NAS or VM.

They don't clash. They just do different jobs:

LocalSend is the courier.
Syncthing is the filing system.

Conclusion

You don't have to live in a cloud provider's ecosystem. Don't want AI scanning or reading confidential documents? Share them locally, quickly and securely with Syncthing and LocalSend.

If you run an office, setting these up is a tech upgrade that pays off every day: fewer "can you email that to me?" requests, fewer USB sticks, fewer mystery versions of files and faster turnarounds.

Share Files Locally and Securely with LocalSend + Syncthing

LocalSend: “AirDrop for everyone”