Guides and the grid help you position images or elements precisely. Guides appear as nonprinting lines that float over the image. You can move and remove guides. You can also lock them so that you don’t move them by accident.
Smart Guides help you align shapes, slices, and selections. They appear automatically when you draw a shape or create a selection or slide. You can hide Smart Guides if you need to.
The grid is useful for laying out elements symmetrically. The grid appears by default as nonprinting lines but can also be displayed as dots.
Guides and grids behave in similar ways:
Selections, selection borders, and tools snap to a guide or the grid when dragged within 8 screen (not image) pixels. Guides also snap to the grid when moved. You can turn this feature on and off.
Guide spacing, along with guide and grid visibility and snapping, is specific to an image.
Grid spacing, along with guide and grid color and style, is the same for all images.
Choose View > New Guide. In the dialog box, select Horizontal or Vertical orientation, enter a position, and click OK.
Drag from the horizontal ruler to create a horizontal guide.
Hold down Alt (Windows) or Option (Mac OS), and drag from the vertical ruler to create a horizontal guide.
Drag from the vertical ruler to create a vertical guide.
Hold down Alt (Windows) or Option (Mac OS), and drag from the horizontal ruler to create a vertical guide.
Hold down Shift and drag from the horizontal or vertical ruler to create a guide that snaps to the ruler ticks. The pointer changes to a double-headed arrow when you drag a guide.
Drag the guide to move it.
Change the guide from horizontal to vertical, or vice versa, by holding down Alt (Windows) or Option (Mac OS) as you click or drag the guide.
Align the guide with the ruler ticks by holding down Shift as you drag the guide. The guide snaps to the grid if the grid is visible and View > Snap To > Grid is selected.
- Option (Mac) / Alt (Windows) + drag a layer: When you drag a layer while keeping the Option (Mac) or Alt (Windows) key pressed, Photoshop displays reference measurement guides showing the distance between the original layer and the duplicate layer. This feature works with both the Move and Path Selection tools.
- Path measurements: Photoshop displays measurement guides while you're working with paths. Measurement guides are also displayed when you select the Path Selection tool and then drag a path within the same layer.
- Cmd (Mac) / Ctrl (Windows) + hover over a layer: You can view measurement guides while working with layers. With one layer selected, hover over another layer with the Cmd (Mac) or Ctrl (Windows) key pressed. You can use arrow keys in conjunction with this feature to nudge the selected layer.
- Distances from the canvas: When you hold down the Cmd (Mac) or Ctrl (Windows) key while hovering outside a shape, Photoshop displays distances from the canvas.