Single Row Marquee Tool in Photoshop Explained

This guide explains the purpose, core functionality, and practical applications of the Single Row Marquee Tool in Adobe Photoshop. You will learn what makes this tool unique among Photoshop's selection features, where to find it in the workspace, and the specific design and editing workflows where it provides the most value.

The Single Row Marquee Tool is a specialized selection tool designed to select an exact horizontal line of pixels across the entire width of an image canvas. Regardless of the canvas width or the document resolution, the selection is consistently locked at exactly 1 pixel in height.

You can find the tool in the Tools panel grouped beneath the standard Rectangular Marquee Tool. To access it, click and hold (or right-click) the Rectangular Marquee Tool icon, then select "Single Row Marquee Tool" from the flyout menu.

Unlike standard selection tools that require you to click and drag to define an area, the Single Row Marquee Tool operates with a single click. When you click anywhere on the canvas, Photoshop instantly generates a 1-pixel-high selection across the entire horizontal axis at that precise Y-coordinate.

The tool serves several specific functions in graphic design, web production, and photo retouching:

  • Creating Precise Dividers and Lines: By filling or stroking the 1-pixel selection (via Edit > Fill or Edit > Stroke), you can create clean, crisp horizontal borders, rules, and dividers without needing to manually draw vector paths or line shapes.
  • Creating Seamless Gradient Strips: In web design, you can select a 1-pixel slice of a gradient or background texture and stretch it vertically across an entire layout to create lightweight repeating background elements.
  • Correcting Scan Lines and Artifacts: When restoring digitized film or repairing corrupted digital images, the tool allows you to isolate and sample a single line of faulty pixels to blend or replace them with adjacent data.
  • Edge Alignment and Measurement: Designers frequently use the tool to check pixel alignment across wide canvases or to create temporary 1-pixel visual reference guides.

Once a row is selected, it functions like any other Photoshop selection. You can invert it, add or subtract from it using modifier keys (Shift to add, Alt/Option to subtract), copy the data to a new layer, or apply adjustment layers directly to that single pixel row.