Siege Media

What is contrast ratio?

Contrast ratio is the difference between the maximum and minimum brightness of a computer display. It helps measure the readability of your content. The higher the number, the better the readability. Lower numbers (and red on our tool) indicate poor readability.

What is relative luminance?

As defined by the World Wide Web consortium, relative luminance is the relative brightness of any point in a colorspace, normalized to 0 for the darkest black and 1 for lightest white.

What is a good contrast ratio?

A good contrast ratio is any number above 4.5 or 4.5:1, assuming small text exists in your content. According to the World Wide Web consortium, larger text can dip to 3:1, but would ideally be higher.

I got an error in Google Lighthouse that says: “background and foreground colors do not have a sufficient contrast ratio.” What should I do?

You’re in the right place! Use the tool to modify the background and font colors to create a more accessible website. Once implemented, you should no longer receive this error.