What is collaborative text editing?

Collaborative text editing lets several people work on the same text at the same time, each from their own computer. Everyone sees the others' changes within a fraction of a second, along with where the others are typing, so a document can be written, reviewed and corrected together instead of being passed back and forth.

The hard part is typing at the same moment. If two people change the text at once, their changes have to be combined so that both survive and everyone ends up with exactly the same text. Real-time editors do this by sending small changes instead of the whole document, and by having one place decide in which order they apply.

Tool description

This tool is a shared plain text editor. Open it, send the link to others, and everyone edits the same text in real time. Each person's cursor and selection appear in their own color, with their name, and the list on the right shows who is in the room.

It needs no account and no setup: the room is created when the page opens, and the text can be copied or downloaded at any time.

Features

  • Real-time editing - changes from everyone appear instantly, and typing at the same moment is merged without losing anyone's text
  • Cursors and selections - see where each person is typing, in the color shown next to their name
  • Share link - the room ID goes in the page address, so sharing the link is all it takes to invite someone
  • Copy and download - keep a copy of the text as a .txt file whenever you like

How it works

When the page opens, it creates a room on the sync server and puts its link in the address bar. Everyone who opens the link joins the same room and sees the same document.

Every change is sent to the server as a small description of what changed - which characters were inserted or deleted where - instead of the whole text. The server puts changes from everyone in a single order, moves a change that was made on top of an older version past the ones that came first, and passes the result on to everyone else. Your own typing shows up right away, and changes from others are merged around it, so nobody's typing gets lost when two people edit at the same moment.

The document is kept in the server's memory only while the room is open. If you reload the page, you get back into the room with the text as it was; once everyone has left, the room and its text are gone.

Limitations

  • A room holds up to 20 people and 100,000 characters.
  • Nothing is stored after a room closes. Download the text before the last person leaves.
  • Very fast or very large changes, such as pasting the whole document many times in a row, are refused and the editor reloads the room's text.
  • Opening a room link in another of the collaborative editors (for example a SQL room in the JavaScript editor) shows "Room not found": each room belongs to one language.

Tips

  • Hover over another person's cursor to see their name.
  • Reloading the page keeps you in the same room, with the text as it was.