How to Draw Straight Lines in GIMP with Shift

Drawing perfectly straight lines in GIMP does not require a dedicated line tool; instead, it relies on the Shift key modifier in combination with standard painting tools. By mastering the use of Shift to connect two points, alongside the Ctrl key to constrain angles, you can quickly draw precise horizontal, vertical, and angled lines across your canvas.

The Basic Straight Line (Any Angle)

To draw a straight line at any freeform angle between two points:

  1. Select a Painting Tool: Choose any brush-based tool from the toolbox, such as the Paintbrush, Pencil, Airbrush, or Eraser.
  2. Place the Starting Point: Click once on the canvas where you want your line to begin.
  3. Hold the Shift Key: Press and hold down the Shift key. You will see a straight preview line extending from your initial click point to your current mouse cursor position.
  4. Place the Ending Point: While continuing to hold Shift, move your cursor to your desired end position and click. GIMP will immediately render a straight stroke between the two points.

To draw continuous connected straight lines, keep holding Shift and continue clicking additional points across the canvas.

Constraining to Horizontal, Vertical, and 15-Degree Angles

To ensure a line is perfectly horizontal, vertical, or locked to a specific diagonal:

  1. Click the Starting Point: Click once on the canvas to set the anchor.
  2. Hold Shift + Ctrl: Press and hold both the Shift and Ctrl keys simultaneously (use Cmd on macOS).
  3. Move the Cursor: As you move the mouse, the guide line will snap in fixed 15-degree increments.
    • Move directly left or right for a 0° or 180° horizontal line.
    • Move directly up or down for a 90° or 270° vertical line.
    • The status bar at the bottom of the window displays the exact angle and length in pixels.
  4. Click to Draw: Left-click once to commit the stroke, then release the keys.