Screenshots on this website are 700px wide and look something like this:

• It’s best to use an image that is wider than it is tall (ratio of 2:1 or more).
• Crop images to focus only the essential parts, but make sure you retain context.

A screenshot with a highlighted area looks like this:

How to create a screenshot with a highlighted area

Photoshop

• Open the screenshot in Photoshop.
• Select the area you want to highlight using the Rectangular Marquee tool.
  • You can also use the Polygonal Lasso tool (click and hold on Lasso) to make complex shapes.
• Select > Inverse
• Image > Adjustments > Levels…
• Change Output Levels maximum value from 255 to 100

To export from Photoshop, use File > Export > Export as…

Preview (Mac)

• Open the screenshot in Preview.
• Highlight a section using Tools > Annotate > Mask.
• Resize the image to 700px wide using Tools > Adjust size.

To export from Preview, use File > Export…