Photoshop Selection Modifier Keys

Mastering selection tools in Adobe Photoshop requires understanding how keyboard shortcuts modify your active selections. This guide outlines the essential modifier keys used to add to, subtract from, and intersect selections on both Windows and macOS, enabling a faster and more precise image-editing workflow.

Add to an Existing Selection

To expand an active selection, use the Shift key.

  • Windows: Hold Shift while dragging or clicking with any selection tool.
  • macOS: Hold Shift while dragging or clicking with any selection tool.

When you hold Shift, a small plus sign (+) appears next to the cursor, indicating that the new area you define will combine with your current selection.

Subtract from an Existing Selection

To remove a portion of an active selection, use the Alt (Windows) or Option (macOS) key.

  • Windows: Hold Alt while using a selection tool over the selected area.
  • macOS: Hold Option while using a selection tool over the selected area.

Holding this key displays a small minus sign (-) next to your cursor. Any pixels included inside the new boundary will be removed from the existing selection.

Intersect with an Existing Selection

To keep only the overlapping area between your current selection and a new one, combine both modifiers.

  • Windows: Hold Shift + Alt simultaneously while making a selection.
  • macOS: Hold Shift + Option simultaneously while making a selection.

When these keys are engaged, a small x appears next to the cursor. Once you release the mouse button, Photoshop discards everything except the area where the two selections overlap.

Using Modifiers with Layers and Channels

These modifier keys also apply when loading selections from layers, paths, or channels:

  • Add Layer Selection: Ctrl + Shift + Click on a layer thumbnail (Windows) or Cmd + Shift + Click (macOS).
  • Subtract Layer Selection: Ctrl + Alt + Click on a layer thumbnail (Windows) or Cmd + Option + Click (macOS).
  • Intersect Layer Selection: Ctrl + Shift + Alt + Click on a layer thumbnail (Windows) or Cmd + Shift + Option + Click (macOS).

Key Takeaway

  • Shift = Add
  • Alt / Option = Subtract
  • Shift + Alt / Shift + Option = Intersect

Always press and hold the modifier key before clicking, start drawing your new shape, and release the mouse button before releasing the keyboard keys to ensure the modifier is properly registered.