Accessibility tools are designed to support testing and evaluation practices and streamline the review of web pages and content. Site-wide evaluation tools can spider through websites and offer a broad perspective as to the issues throughout the site. In contrast, in-browser tools will provide specific information as to any accessibility issues at a single-page level.
It is important to remember that any automated accessibility tool is limited to evaluating the technical criteria. For example, an automated tool can test as to whether or not an image has a text equivalent, but these tools cannot determine the extent to which that text equivalent is appropriate.
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