Is TETR.IO still online?

What is TETR.IO?

“Puzzle together in this free-to-win modern yet familiar online stacker in the same genre as Tetris. Play multiplayer games against friends and foes all over the world, or claim a spot on the leaderboards - the stacker future is yours!”

In this directory, TETR.IO sits in the modern indie collection and is tagged puzzle (2 games), stacker (2 games) and 1v1 (13 games). It launched in 2020, which places it on our timeline.

Fact file

First released

May 21, 2020

Source: Wikidata (CC0). Wikidata is community-edited; corrections welcome there.

How to play

1. 01Open tetr.io in a desktop or mobile browser. It is the official site; avoid “unblocked” mirrors.
2. 02The homepage doesn't say whether you need an account. Many games here let you play as a guest and register later to keep progress.
3. 03The homepage doesn't list controls, so we don't guess. Most games show a tutorial or a “how to play” screen on first launch.
4. 04Playing with friends: Play multiplayer games against friends and foes all over the world

Platform notes

Browser

Plays in the browser from tetr.io (our inclusion rule).

Account

Not stated on the homepage.

Mobile

Not stated on the homepage.

Status history

Per-check history started on Oct 29, 2026. Status changes across all games are in the status log.

TETR.IO: FAQ