LaptopDrop

An AirDrop-style app for your local network. Send files and text from your laptop to your phone (or to another laptop) over Wi-Fi. No internet, no accounts, no cloud, and no app to install on the phone.

npx laptopdrop@latest

Status: early prototype. The UI is basic and only the core functionality works. Contributions and feedback are welcome.

Features

• Send any file type (images, documents, PDFs, videos, archives, and more) and text
• Send from a laptop to a phone or to another laptop
• Phone connects by scanning a QR code and just opens a web page (no install)
• Laptop-to-laptop discovery using mDNS
• Receiver must tap Accept before anything is saved or shown
• Transfers expire after 60 seconds if not accepted
• Files stay on your local network and never touch the cloud
• Image thumbnails and previews; other files show their name and size
• Light and dark mode

How it differs from real AirDrop

Real AirDrop uses Bluetooth and peer-to-peer Wi-Fi, so devices can share just by being close together. LaptopDrop cannot do that. Both devices must be on the same Wi-Fi network, and a phone connects by scanning a QR code instead of by proximity.

Current limitations

• Phones are receive-only for now (they cannot send)
• Executable and script files are blocked for safety (see Security notes)
• Large files (such as videos) depend on your network speed and the size limit in server.js
• Plain HTTP only (no encryption yet)
• Basic UI

Tech stack

• Node.js + Express
• ws (WebSockets) for real-time events
• bonjour-service (mDNS) for laptop discovery
• multer for file uploads
• qrcode for the connection QR code
• Plain HTML, CSS and JavaScript frontend

Requirements

• Node.js 20 or newer
• Laptop and phone on the same Wi-Fi network

Install and run

Option 1: npx (no install)

npx laptopdrop@latest

Option 2: install globally

npm install -g laptopdrop
laptopdrop

Option 3: from source

git clone <your-repo-url>
cd laptopdrop
npm install
npm start

The terminal prints two addresses and a QR code:

Open on this laptop: http://localhost:3000
Open on your phone:  http://192.168.x.x:3000

Updating

• npx laptopdrop@latest always fetches the newest version.
• If installed globally: npm update -g laptopdrop

Usage

Laptop to phone

1. Run LaptopDrop on the laptop. The page opens at http://localhost:3000.
2. On your phone, scan the QR code (from the terminal or the page), or type the "Open on your phone" URL into the phone's browser.
3. The phone appears under Nearby devices on the laptop page.
4. Select the phone, add files or type text, then click Send.
5. On the phone, tap Accept, then Download the files or Copy the text.

Laptop to laptop

1. Run LaptopDrop on both laptops (same Wi-Fi).
2. Each laptop shows the other under Nearby devices.
3. Select it, add files or text, and click Send.
4. The receiving laptop clicks Accept. Files are saved to ~/Downloads/LaptopDrop.

Network setup

Both devices need to be on the same local network. The network does not need internet access.

| Setup | Works? | Notes | |---|---|---| | Home or office Wi-Fi router | Yes | Most reliable option | | Laptop's Mobile Hotspot, phone joins it | Yes (tested) | Windows: Settings > Network & Internet > Mobile hotspot. The laptop address is usually 192.168.137.1 | | Second phone's hotspot, laptop and main phone both join | Usually | Both devices are ordinary clients | | Laptop joins the phone's hotspot, phone opens the page | Yes (tested) | Turn on the phone's hotspot, connect the laptop to it, then open the laptop's URL on the phone. On some phones the browser may show "No internet connection"; if so, use one of the other setups |

Troubleshooting

Phone says "No internet connection" or the page won't load

• Confirm both devices are on the same network (not one on mobile data).
• If your phone is the hotspot host and the page still won't open, try one of the other setups in the table above.
• On Android, if it warns that the Wi-Fi has no internet, choose to stay connected, or turn mobile data off temporarily.

Phone can't reach the laptop's address

• Allow Node.js through the firewall on private networks when Windows or macOS prompts. If you missed the prompt, allow it manually in firewall settings.
• Check the IP in the terminal matches your network range (e.g. 192.168.x.x). If it shows a virtual adapter's address (VirtualBox, Docker, WSL, VPN), the QR code points to the wrong place.
• Use the exact port shown in the terminal. It moves to 3001 and up if 3000 is busy.
• Test by opening http://<laptop-ip>:<port> in the phone's browser.

Device doesn't appear in Nearby devices

• Some college, office and public Wi-Fi networks block device-to-device traffic ("client isolation"). Use a home router, a laptop hotspot, or a phone hotspot with both devices as clients.
• Make sure the phone's page is still open and connected.

A file was skipped or rejected

• Executable and script types (for example .exe, .bat, .ps1) are blocked. See Security notes.
• Check the file is under the size limit set in server.js.

Large file transfer fails or stalls

• Keep both devices on a strong Wi-Fi connection and keep the phone page open until the download finishes.
• Make sure the sending and receiving laptops have enough free disk space, since files are staged in a temporary folder.

Phone browser warns the site is "not secure"

• Expected: LaptopDrop uses plain HTTP. This is fine on a network you trust, but avoid using it on public Wi-Fi.

Copy button doesn't work on the phone

• Clipboard access can be restricted over plain HTTP. Long-press the text and copy manually.

Security notes

• Nothing is saved or shown until the receiver accepts.
• Pending transfers expire after 60 seconds and temporary files are deleted.
• File names are sanitized to prevent path traversal.
• These file types are blocked by default: .exe, .msi, .bat, .cmd, .com, .scr, .ps1, .vbs, .vbe, .wsf, .hta, .jar, .lnk, .reg, .dll. The list is BLOCKED_EXT in server.js.
• Only image files are ever displayed inline on the phone. Everything else is served as a download.
• Received text is escaped before display.
• Only the laptop running the server can send; phones can only receive.
• Traffic is not encrypted yet, so use it only on networks you trust.
• Only accept files from devices and people you recognize.

Configuration

Settings are in the CONFIG object at the top of server.js:

| Setting | Default | Description | |---|---|---| | START_PORT | 3000 | Starting port (tries the next ones if busy) | | MAX_FILE_SIZE | 100 MB | Maximum size per file. Increase it to send large videos | | MAX_FILES | 20 | Maximum files per transfer | | PENDING_TIMEOUT_MS | 60000 | How long a request waits for Accept | | ACCEPTED_KEEP_MS | 10 min | How long files stay available for the phone to download after Accept | | BLOCKED_EXT | see above | File extensions that are rejected | | OPEN_BROWSER | true | Open the page automatically on start |

Project structure

laptopdrop/
├── package.json
├── bin/
│   └── laptopdrop.js  # CLI entry point (npx laptopdrop)
├── server.js          # Express, mDNS, WebSocket, transfer logic
├── public/
│   ├── index.html     # Laptop (host) UI
│   ├── app.js
│   ├── receive.html   # Phone (receive-only) UI
│   ├── receive.js
│   └── style.css
├── LICENSE
└── README.md

Roadmap

• [x] Publish as an npm package
• [x] Support for documents and other file types
• [ ] Let phones send files to laptops
• [ ] Better UI design
• [ ] HTTPS with a self-signed certificate
• [ ] Electron desktop app with a tray icon
• [ ] Transfer history and progress improvements

Contributing

Issues and pull requests are welcome. If you have ideas or run into problems, please open an issue.

License

MIT