How to Customize Column Widths in Mac OSX Finder

Finder is a great tool for looking at your files, but having to resize columns to see a long file name can be inconvenient. The handle (two small vertical lines) at the bottom of the column allows you to resize the column. Double-clicking on the handle resizes the column to fit the widest file name. Holding Option while dragging a handle sets that custom width for every future Finder window.

Control (Right) click on a column handle and you’ll see three options: Right Size This Column, Right Size All Columns Individually, and Right Size All Columns Equally. The first option makes that column the width of the longest name in only this column (the other columns remain unchanged). The second option does this same thing for each individual column that contains items (so each column will be a different size based on the length of names within each column). The third imposes the widest column length on all the columns.