A scan report and an audit report serve different purposes, cover different ground, and carry different weight. A scan report is the output of an automated check that evaluates code against a subset of Web Content Accessibility Guidelines (WCAG) criteria. An audit report is the output of a thorough human evaluation that covers the full range of WCAG conformance requirements. Understanding what each delivers helps organizations decide when to use one, the other, or both.
| Key Point | What It Means |
|---|---|
| Coverage | Scan reports cover approximately 25% of WCAG issues. Audit reports cover the full scope of WCAG criteria at a given conformance level. |
| Source | Scan reports are generated by automated tools. Audit reports are produced by accessibility professionals conducting a (manual) evaluation. |
| Detail Level | Scan reports list flagged code patterns with locations. Audit reports include contextual analysis, user impact assessment, and remediation guidance. |
| Use Case | Scan reports work well for ongoing monitoring. Audit reports serve as the basis for remediation planning and conformance documentation. |
What a Scan Report Contains
A scan report is generated after automated software loads a web page and evaluates its HTML, CSS, and ARIA attributes against a set of programmatically testable WCAG criteria. The report typically lists each flagged issue by type, provides the code snippet or element location, and categorizes the issue by WCAG criterion.
Because automated scans can only flag approximately 25% of accessibility issues, the scan report reflects a narrow slice of overall conformance. It captures patterns like missing form labels, empty link text, or incorrect heading order. It does not capture anything that requires human judgment, such as whether alternative text accurately describes an image or whether a custom interaction is operable with a keyboard.
Scan reports are useful for tracking recurring patterns over time, especially when scans run on a scheduled basis as part of a monitoring program.
What an Audit Report Contains
An audit report is the product of a full evaluation conducted by accessibility professionals. The evaluation includes screen reader testing, keyboard testing, visual inspection, code inspection, and an automated scan used as one component of the review.
The report documents every issue the audit identifies across each page or screen evaluated. Each issue entry typically includes the WCAG criterion it relates to, the specific location on the page, a description of the issue in context, its impact on users, and recommended remediation steps. Audit reports also note the conformance level being evaluated against, such as WCAG 2.1 AA or WCAG 2.2 AA.
Because the evaluation involves human judgment, the audit report captures the 75% of issues that scans miss entirely. It addresses areas like content structure, interactive component behavior, reading order, and whether assistive technology users can complete tasks.
How They Differ in Scope and Reliability
The core difference is scope. A scan report tells you what automated checks could detect on the pages it reached. An audit report tells you the full conformance status of the pages a professional evaluated.
Scan reports may include false positives, where the tool flags something that is not actually an issue in context. They may also miss entire categories of issues that require visual or interactive evaluation. Audit reports are verified by the evaluator, which means each identified issue has been confirmed as a real conformance gap.
When Each Report Type Applies
Scan reports fit into workflows where frequency matters. Running weekly or monthly scans produces a stream of reports that show whether new issues are appearing across a site. This is particularly useful during active development cycles.
Audit reports fit into workflows where depth and accuracy matter. Organizations conducting an audit typically do so when preparing for procurement requirements, documenting conformance for legal purposes, or planning a remediation project. The audit report becomes the roadmap for what to fix, in what order, and why.
Most organizations benefit from both: scan reports for continuous monitoring, and audit reports for periodic full-scope evaluation. Neither replaces the other.