The Positioner is a ScriptUI panel for After Effects that aligns, pins and auto-scales layers to the edges of a composition or to other layers. As a design changes, positioned layers stay responsive, and the whole workflow runs through a clean visual interface built for fast positioning.
The panel offers pinning to composition edges and to layer edges, plus ten scale modes: Fit, Fit Width, Fit Height, Fill, Stretch, Stretch Width, Stretch Height, Shrink, Shrink Width and Shrink Height. Padding can be applied uniformly or set individually for left, top, right and bottom, and Limit Size keeps width or height within a set percentage. A companion tool, Box It!, builds self-resizing text boxes, lower thirds, chat bubbles and similar elements.
The Positioner requires After Effects CC 2024 and newer, with the Expressions Engine set to JavaScript in Project Settings. Install it through the aescripts + aeplugins manager app, then open it from Window > The Positioner. This catalog lists the script as free.