PMTiles Version 3: Disk Layout and Compression

Following last week’s post explaining the tile-addressing schema in PMTiles version 3, Brandon Liu now discusses its compression approach reducing the disk space required to store a global tile dataset to only 91.6 MB.

Update: Brandon clarified on Twitter, the 91.6 MB mentioned above only holds the data required to map Z,X,Y coordinates to the corresponding Tile ID. The actual global map data set is 80GB. (15 August 2022)