格 千格 KiloCell

Color Contrast Checker for Colour Contrast

Ensure that your design meets accessibility standards. Real time detection of text and background contrasts, appropriate for WCAG 2.1.

Contrast Test Title

This is a test text. By checking the contrasts, we can ensure that content is easy to read for all, including visually impaired users.

21.00
Contrast Rate

WCAG AA (normal text)

Adopted (4.5:1)

WCAG AA (large text)

(3.0:1)

WCAG AAA (normal text)

Pass (7.0:1)

WCAG AAA (large text)

Adopted (4.5:1)

Solving specific problems: Why is the contrast of colour so important for SEO and UX?

While pursuing visual beauty, many designers tend to ignore it. Accessibility 。 If text is kept low against background, it not only prevents visually impaired users from reading, but even ordinary users find it difficult to move equipment in a strong light environment. Color Contrast Checker Helps you quantify this readability, and ensures that your design meets the global WCAG standard.

1. What is the WCAG standard?

WCG (Web Contact Accessibility Guides) by W3C A series of web-based accessibility guides has been developed. In terms of colour contrast, it defines two levels:

  • AA Level (minimal contrast): Requires at least the contrast of normal text to 4.5:1 , large text (18pt or 14pt thick) is at least 3:1 。 This is the basic standard that most commercial websites should meet.
  • AAA Level (enhanced contrast): Requires normal text to be at least 7:1 , the large text is at least 4.5:1 。 This applies to situations where the requirement for readability is extremely high (e.g., government or medical websites).

2. Potential negative impact of low contrasts on SEO

Although contrast itself is not a direct ranking signal, it can indirectly affect SEO by:

  • User behaviour indicators: Google may consider your page to be of low quality if users leave quickly because they can't see what they want, which leads to an increase in the rate of jump.
  • Mobile device fit: The Lighthouse audit tool for Google will include low contrasts as accessibility errors, which will reduce the overall rating of the page.
  • Brand trust: Professional and easy to read designs can significantly enhance the professional image of brands in the minds of users.

3. Addressing the challenge of alignment: How to adjust the colour of non-compliance?

If your brand size fails to pass the test, you can try the following strategies:

  • Lightening: Keep color constant and only adjust the colour visibility (Lightness). Usually fine-tune 5-10% to pass the AA level test.
  • Add word-weight: If the contrast is between 3:1 and 4.5:1, adding text to the text (Bold) will often allow it to meet the criterion of "large text".
  • Using a supporting background: If text had to be placed on the background map, a semi-transparent dark mask could be added to enforce the increase in the scale.

4. How can the design process be integrated?

We suggest this tool be used at the first stage of the UI design. Enter your Hex directly. Colour values, visual feedback for the preview area. Only after passing the design of the AA level test is a person eligible to go online in the production environment.