A carrier for tools, painters' supplies and the like, for use on the top of a folding ladder, is invertible, providing a selection between two tray-like receptacles of different depths having a common planar bottom which rests on the ladder top. The rectangular wall of the inverted tray portion holds the carrier securely on the ladder top. Handles, drawn upward to whichever side is presented upward and then inward, spring back and retract out of the way by gravity.