Flood Select Tool Flooding pixel selections

Using the Flood Select Tool you can define a selection of similar color value pixels with a single click.

Flooding and tolerance

When using the Flood Select Tool, Affinity Photo will analyze the target (clicked) pixel and use its color value to create a selection which includes pixels with similar color values.

Before and after pixel clicked.

The number of pixels selected is determined by the tool's tolerance setting. The higher the tolerance the more variance allowed between the target pixel and selected pixels. Therefore a higher tolerance will likely lead to more pixels being included in the selection.

This makes selecting an area of similar color and tone effortless.

Contiguous behavior

By default, flood selecting is contiguous. This means pixels with similar color values must be adjacent to one another to be selected. Therefore, pixels must be directly connected to the target pixel (or other selected pixels) to be selected. If there is a high contrast edge between areas of similar color, the pixels on the opposite side of the edge will not be selected using a single click.

As an alternative, the contiguous behavior can be switched off. This will mean pixels of similar color to the target pixel will be selected regardless of their position within the image.

Difference in selection method with contiguous on (before) and off (after).
Flood Select Tool To create a pixel selection:

With the Flood Select Tool selected:

  1. (Optional) On the context toolbar, set the Tolerance.
  2. Click on your page.
Flood Select Tool To create a pixel selection using multiple target pixels:

With the Flood Select Tool selected:

  1. On the context toolbar, set the Mode to Add.
  2. Click on your page.
  3. Repeat step 2 as needed.
Flood Select Tool To switch off contiguous selection: