Send a link or a screenshot to the computer next to you.
Two computers on the same network see each other from the menu bar, and you send text or an image across — Mac to Windows included. No server, no account, nothing leaves your network. Text lands on the clipboard, images in Downloads, and nothing is used until you accept it.
Open the same tab on both computers. That is the setup.
The widget starts behind a single button, because turning it on opens ports and — on macOS — asks for the “Local Network” permission, and a permission prompt with no explanation is an uninstall. So it explains itself first, you press Enable, and each machine announces itself on the network under its own name (the machine name, which you can rename to whatever you like).
From there the other computer appears in the list with its address, and sending is one click. That opt-in is not remembered between sessions: every time you come back to the widget you enable it again, which is the flip side of the promise below — nothing is listening while you are not there.
- Discovery is a broadcast on your own network; the transfer is machine to machine
- Both sides need the tab open — the ports close when you look away
- Devices re-announce every few seconds and drop off the list after about twelve
- Lives in the Share tab, next to Clipboard history
- On macOS, a button opens the exact System Settings pane for the permission
Discovers other Toolbox instances on your network and sends them text or images. When you enable it, macOS will ask for “Local Network” permission — it’s needed to find the other devices. Content travels unencrypted: use it only on trusted networks.
Enable network sendingText goes to the clipboard. Images go to Downloads. Neither happens behind your back.
What arrives shows up as a card with the sender’s name and a preview, and two buttons: Copy (or Save) and Discard. Until you press one, nothing has touched your clipboard or your disk — a machine on your network can offer you something, it cannot put it anywhere. Accept a text and the next paste is it; accept an image and it is a PNG in Downloads, never overwriting a file that was already there.
Compose by typing, by attaching an image, by pasting one from the clipboard or by dropping one on the panel. Limits are 256 KB of text and 25 MB per image, and what comes in is not trusted: the image is really decoded — with caps on dimensions and memory, so a tiny file cannot claim to be 30,000 pixels wide — and then re-encoded to PNG, so the sender’s raw bytes are never passed along.
- Filenames are stripped to a plain name: no paths, no invisible characters
- A taken name becomes “name (1).png” instead of replacing anything
- Text must be valid UTF-8 or it is refused
- Images only — no PDFs, no zips, no arbitrary files
It crosses the Mac–Windows line. It does not match AirDrop on secrecy.
AirDrop is excellent and stops at the edge of Apple’s ecosystem: the moment one of the two machines runs Windows, it is not an option. This is the gap this widget fills — same network, either direction, no account. But the comparison has to be honest in both columns: AirDrop encrypts what it sends and this does not. Here the content crosses your local network in the clear, which is fine for the office desk with your own two machines on it and wrong for airport WiFi.
The second difference is scope. AirDrop moves any file; this moves text or an image, and it needs Toolbox open on both sides rather than being a system service. In exchange you get something AirDrop has no notion of: text that arrives directly on the clipboard of the other machine, which is what you actually want when you are sending yourself a URL.
- Use it on networks you trust — your own home or office, not a café
- The shared code controls who can send to you; it does not hide the traffic
- For anything confidential, use a tool that encrypts in transit
A code decides who can send to you — and says nothing about who can read it.
Leave it empty and any Toolbox on your network can offer you something (you still have to accept it). Set one — the dice button makes a readable ABC-DEF, with I, O and Q left out so nobody hears “eye” and types a 1 — and only machines carrying the same code get that far.
The check is a challenge-response, not a password sent across: the receiving side issues a fresh random nonce for every connection and the sender answers with an HMAC of the code over that nonce, compared in constant time. A wrong code is refused before a single byte of content is read, and an answer captured once is useless against the next nonce. What it does not do — and this is the part worth repeating — is encrypt the content that follows.
- One port, open only while you are looking at the widget
- Unknown connections are dropped before the handshake even starts
- Announcements from a single source are rate-limited, so nobody floods the list
- No agent tools, and agent access ships off for this widget on purpose
If you set a code, only devices with the SAME code can send to you. Note: content travels unencrypted over the local network.
It comes with Toolbox. There is nothing to install.
Send to another computer is built into Webstarted Toolbox, the app that lives in your menu bar on macOS and your system tray on Windows — so it is already there the moment you install it, in the Share tab. These are a few of its neighbors:
Questions, answered.
Does it work between a Mac and a Windows PC?
Yes — that is the point of it existing. Both machines run Webstarted Toolbox and sit on the same local network, and each one sees the other in the list by its machine name. Nothing about the transfer is platform-specific: text arrives as text, an image arrives as a PNG. There is no mobile version, so phone-to-laptop is not what this does.
Is the transfer encrypted?
No, and it would be dishonest to bury that. The content travels in the clear over your local network, which is why the widget says so on the screen where you enable it: use it on networks you trust. What the optional shared code adds is authentication — who is allowed to send to you — not secrecy. If what you are moving would hurt you in the hands of whoever else is on that WiFi, this is the wrong tool for it.
Does anything go through a server or the internet?
No. Discovery is a broadcast on your own network and the transfer is a direct connection between the two machines, on a single port they both open. There is no account, no relay, no cloud storage and nothing to sign into — which also means the two computers must genuinely be on the same network, not merely both online.
Why doesn’t the other computer show up?
Almost always one of three things. Both machines need the widget open — the ports only exist while you are looking at that tab, so you open the same tab on both. On macOS, Toolbox needs the “Local Network” permission; the widget has a button that opens exactly that pane in System Settings so you can check the box. And the network has to actually pass broadcasts: a guest network with client isolation, two different WiFi bands routed apart, a VPN capturing the traffic, or two subnets will all leave the list empty. Devices announce themselves every few seconds and drop off the list about twelve seconds after they stop.
Can I send a PDF, a zip, or any file?
Not today: it sends text or an image, and the attach button only accepts images. That is a real limit worth stating rather than discovering — for a contract or an archive, this widget is not the tool. What it is very good at is the thing you actually do twenty times a day: moving a URL, a snippet, an error message or a screenshot from the machine on the left to the machine on the right.
Where does what I receive end up?
Text goes to the clipboard of the receiving machine, so the next paste is it. An image is saved to the Downloads folder as a PNG, and it never overwrites: a name already taken gets a numbered one instead, and the widget offers to reveal the file. Neither happens on its own — an incoming item shows up as a card with a preview and two buttons, and until you press Copy or Save nothing has touched your clipboard or your disk.
What is the shared code for?
It is optional, and it decides who may send to you: set one on a machine and only devices carrying the same code can deliver anything to it. Under the hood it is a challenge-response — the receiver issues a fresh random nonce per connection and the sender answers with an HMAC of the code over that nonce, compared in constant time — so a wrong code is refused before a single byte of content is read, and a reply captured once cannot be replayed later. The dice button generates a readable code like ABC-DEF, with I, O and Q left out of the alphabet so nobody mistypes them as 1 or 0 while reading it aloud.
How big can something be?
Up to 256 KB of text and 25 MB for an image. The receiving side does not trust what arrives: it checks the magic bytes, really decodes the image with limits on dimensions and memory so a small file cannot claim to be 30,000 pixels wide and exhaust your RAM, and then re-encodes it to PNG — the sender’s raw bytes are never passed along. The filename is stripped down to a plain name too, with no paths and no invisible characters that make a file display as something it is not.
Why does macOS ask for “Local Network” permission?
Because finding the other computer means broadcasting on your network, and macOS gates that. The prompt appears when you press Enable, not when you open the app, which is exactly why the widget starts behind a short explanation instead of asking for a permission out of nowhere. If you dismissed it, the peer list stays empty — and the widget has a button that opens System Settings → Privacy & Security → Local Network so you can turn it back on.
Does it keep a port open in the background?
No. The sockets open when you enable the network in the widget and close as soon as you look away — hiding the popover shuts them, and the enable step is not remembered between sessions, so it is always a deliberate click rather than something inherited from last week. The trade is honest: a discoverable machine is only discoverable while you are at it, and in exchange nothing is listening the rest of the day.
Can an AI agent send things from my machine?
Not today, and this widget is deliberately opted out. Toolbox ships a local MCP server that widgets can expose actions to, and this one exposes none — plus it is marked as off for agents, so if actions are ever added they start disabled and need your explicit consent. Sending data off the machine is the one capability where “on by default” is indefensible.
Is it free?
Yes. Webstarted Toolbox is a free beta, needs no account, and this comes built into the app — it is in the Share tab the moment you install it. Desktop only: macOS menu bar and Windows tray.
Get Webstarted Toolbox
Free to use. Install it on both computers and it is already in the Share tab. macOS 12+ and Windows 10+.
One icon, many small tools
This is just one of the widgets in Webstarted Toolbox. Here are the rest: