Stranger Things 4 was released in two parts in 2022. Volume 1 premiered on May 27, 2022, and Volume 2 followed on July 1, 2022. Details and context

• The fourth season is often referred to as Stranger Things 4 and was released worldwide on Netflix in two volumes. Volume 1 contains seven episodes, while Volume 2 contains two episodes.
• The release strategy was described by the creators as a response to the season’s length, with Volume 1 arriving May 27, 2022, and Volume 2 about five weeks later on July 1, 2022.

If you’d like, I can pull up more sources or summarize the reception and notable aspects of each volume.