# Shared Todo List

> Create a real-time collaborative todo list that syncs between browsers. Share a link — no account, no server, no setup.

## What does this tool do?

The Shared Todo List creates a collaborative task list that multiple people can edit simultaneously. Changes appear in real-time on all connected browsers. Data syncs directly between browsers using WebRTC — no server stores your data.

## How does it work?

1. Visit https://toolscanvas.com/tools/shared-todos
2. A unique room is created automatically with a URL like `?room=abc-123`
3. Share the URL with others — anyone who opens it joins the same room
4. Add, check, and delete todos — changes sync instantly between all open tabs

## How does syncing work?

The tool uses Yjs, a CRDT (Conflict-free Replicated Data Type) library. Each browser maintains its own copy of the todo list. When two people edit simultaneously, changes merge automatically without conflicts. The sync happens over WebRTC peer-to-peer connections — your data goes directly from browser to browser.

## What can I do?

- Add new todos (press Enter or click Add)
- Check/uncheck todos to mark them done
- Delete individual todos
- Clear all completed todos at once
- Undo and redo your own changes
- See how many other people are in the room

## Does data persist?

Each browser saves the todo list in its local IndexedDB. If you close the tab and reopen the same room URL, your data is restored from local storage. However, if ALL participants close their tabs and a new person joins later, they start with a fresh list — there is no central server holding the data.

## Privacy

- All data stays in your browser and syncs directly to peers via WebRTC
- The Yjs signaling server only exchanges connection metadata (IP addresses) to establish the peer-to-peer link — it never sees your todo content
- No accounts, no tracking, no server-side storage

## Limitations

- Requires at least one peer to be online for new joiners to receive existing data
- WebRTC may not work behind some corporate firewalls
- Room URLs are not password-protected (anyone with the link can join)
- Data does not persist if all peers close their tabs before a new peer joins