Grapher Preview can open any GRF, GPJ, or GRT file created in Grapher v2 or later. If you have a Grapher v1 or Grapher DOS file, you can follow these instructions to convert it to a newer format.
Grapher Preview saves GRF, GPJ, and GRT files in the Grapher File (*.grf), Grapher Project (*.gpj), or Plot Template (*.grt) file format. Only Grapher Preview can open files in these formats. If you wish to open the file in an older version of Grapher, you can save GRF, GPJ, and GRT files to any version format back to Grapher v8 by clicking File | Save As, selecting the version you wish under Save as type, giving it a name, and clicking Save.
Note: If you open the file later in Grapher Preview and click File | Save, it will save it in the Grapher Preview format. You must click File | Save As and choose to save it in the older format each time you wish to save it in that older format.
Updated April 15, 2019