> ## Documentation Index
> Fetch the complete documentation index at: https://docs.burakov.net/llms.txt
> Use this file to discover all available pages before exploring further.

# How it works

> Pairing a room, dropping files, and what actually travels between the two devices.

Sidedrop connects exactly two browsers and streams your files directly between them. Here's what
happens from opening the site to a finished transfer.

## One room, three ways to pair

When you open Sidedrop, it creates a private **room** and shows it three ways at once:

* a **share link** you can send through any messenger,
* a **short code** you can read out or type,
* a **QR code** to scan with a phone.

All three point at the same room. Whoever opens it becomes the second device, and the two are
paired. A room holds exactly two — if someone else tries to join a full room, they're told it's
busy rather than silently joining your transfer.

## Symmetric by design

There's no fixed "sender" and "receiver." Once two devices are paired, **either** side can drop
files, and both can send at the same time. That's why the same flow works phone-to-computer,
computer-to-computer, or when you're handing something to another person.

## No accept step

Transfers start the moment you drop something — there's no "accept this file?" prompt on the
other side. The room code is the consent: whoever you shared it with is who you meant to send to.

## What travels between the devices

Once paired, the two browsers open a **direct, encrypted channel** and the file's bytes flow
across it in order, with the receiver confirming what it has as it goes. A live table shows each
item with its progress, speed, ETA, and status. Files, whole folders (the structure is recreated
on the other side), and plain text can all ride the same channel.

<Note>
  The direct channel is end-to-end encrypted. A small signaling server helps the two devices find
  each other at the start, but never carries your files — see [Privacy](/sidedrop/privacy).
</Note>

## When the network wobbles

If the connection drops for a moment or your phone switches from Wi-Fi to cellular mid-transfer,
Sidedrop pauses and re-establishes the path, then continues **from where it stopped** rather than
restarting. This works as long as both tabs stay open; fully closing or reloading a tab ends that
session.