One link puts everyone on the same table, and you see every piece your friends move as they move it.
Most jigsaw sites let you play alone and call it multiplayer if two people happen to be logged in. This one puts you on the same table: you see every piece your friends move, as they move it, with their cursor and their name attached. When somebody joins the puzzle, the pieces they pick up move under your hands.
That is the whole thing. Nobody needs an account, nobody installs anything, and the link works on a phone, a tablet or a desktop. If you would rather read it aloud than paste it, every game also has a four-letter code — no letter O, no number 1, nothing that gets misheard.
Two modes, chosen when you start:
Race mode is worth knowing about because it fixes the one social problem with a shared jigsaw: the fast player finishes it while everyone else watches. Same puzzle, separate tables, and nobody can take a piece you were reaching for.
A shared timer everyone can pause, so a puzzle can be a thing you come back to rather than a single sitting. A scoreboard you can turn off, because keeping score is a good way to make a relaxing activity stressful. And an optional random rotation on the pieces, which roughly doubles the difficulty and is best saved for people who have asked for it.
If you want something to do together at a fixed time, the puzzle of the day is the same picture and the same cut for everyone in the world, with a table of who finished it fastest.