Join and Average: What's the Difference?

I’m often asked: What’s the dif­fer­ence between Join and Average?

To set the stage, Join and Average com­mands are on the Object > Path menu. Select two anchor points with the Direct Selection Tool, then exe­cute the com­mand… And there’s where the dif­fer­ences and sim­i­lar­i­ties come into play.

Join: Combines two open paths or two ends of a sin­gle open path. Select two anchor points and choose Object > Path > Join (or CMD+J / CTRL+J), which will join the two anchor points with a straight path segment.

Average: Moves anchor points to the medi­an aver­age loca­tion between their orig­i­nal loca­tions either hor­i­zon­tal­ly, ver­ti­cal­ly, or both. For exam­ple: Executing the Average com­mand on a path con­tain­ing an anchor point at 1‑inch X & Y (1‑inch across and up), and a sec­ond anchor point at 2‑inches X & Y, will move both select­ed anchor points to 1.5‑inches X & Y. Anchor points will sit atop one anoth­er, but will not be joined. Thus, aver­ag­ing anchor points in two dis­con­nect­ed paths or in the same open path, will not close the path. To close it, you must fol­low up Average with Join.

Or, do them both in one step with CMD+OPT+SHIFT+J / CTRL+ALT+SHIFT+J. This com­mand will use the last cho­sen Average options (Horizontal, Vertical, or Both) to aver­age while join­ing; anchor points will move to the medi­an loca­tion, but instead of over­lap­ping, they’ll be com­bined into a sin­gle anchor point.