How to batch resize multiple images into squares?

Action are recorded Photoshop step. In Adobe added conditional action support a while back where an action cap play(call) other action in the action set the action  is in depending on some conditions.  Actions can test some document conditions and some layer conditions.  And that is all the logic action can muster on their own.  They  can not retrieve information like document  width and document height and use that that information to deal with size.   There few conditions the can test.

Photoshop has an additional automation feature Photoshop Scripting. Actions can use Scripts and Scripts can do Photoshop Actions.

Photoshop Scripts can use logic and can easily do what you want to do.  However scripting is programming you have to program Photoshop Scripts using a scripting language like JavaScript.

What you want to do is simple program.

If document width is greater than document height  canvas size width=document_width  height=document_width

else canvas size width=document_height height=document_height.

Square document canvas sized will not change.   Landscape and portrait document canvas sizes will change canvas will be added to make the document square.

Write that script. Record an action menu File>Scripts>ScriptName then batch that action.

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