From the r/placeAtlas2 Wiki, the r/place encylopaedia

r/place is an experiment on Reddit in which users could edit the canvas at the r/place subreddit by changing the colour of a single pixel with a replacement from a colour palette every 5 to 20 minutes. It may refer to:

  • r/place 2017, the original experiment on April 1, 2017 that lasted 72 hours.
  • r/place 2022, a reboot of the experiment on April 1, 2022 that lasted four days.