The Digital Certainty Index (DCI) is a single, overall score (0–100) that measures the health and effectiveness of your website across three major areas: Quality Assurance, SEO, and Accessibility. It gives you a big‑picture view of how well your site is performing and where you need to focus your improvements.

Screenshot of the Siteimprove DCI Overview page showing the overall DCI score of 74.1, with separate scores for Quality Assurance, SEO, and Accessibility, a graph of score progress over time, and lists of issues to fix and issues already resolved.

How Siteimprove Calculates DCI Points for Each Issue

Siteimprove assigns DCI points based on the impact of an issue across your entire site, not just on one page.

  1. How many occurrences the issue has across the whole site

    An “occurrence” is each place the issue appears, anywhere on your site. More occurrences usually result in a higher potential point gain because it indicates a broader accessibility problem.

  2. How many pages contain the issue

    Even if there are relatively few total occurrences, an issue that appears on more pages signals a more widespread barrier, which affects your score more significantly.

  3. The severity (WCAG conformance level) of the issue

    Level A and AA issues are weighted more heavily in Siteimprove’s scoring model.

  4. The ratio of inaccessible elements to total elements on the site

    For example, if 25 out of 100 images have missing text alternatives, that affects the accessibility score more than 25 missing alt texts on a site with 2 thousand images.