WCAG 2.0 level AA requires a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text. This means that light text can not be used on a white background.
Large text is defined as 14 point (typically 18.66px) and bold or larger, or 18 point (typically 24px) or larger.
WebAIM, a web accessibility solutions company, has a free online contrast checker. Simply set the foreground and background colors, and the checker will automatically provide a pass/fail grade.
Microsoft Office can help you check the accessibility of your files. The most common issue - and easiest to fix - is the absense of alt tags on images. Use the links below to learn how to use Microsoft's Accessibility Checker, and create more accessibile Word documents, Excel workbooks, and PowerPoint presentations.
PDF (.pdf) is simply a file type, such as .txt, .xlsx, or .docx. PDF stands for Portable Document Format.
PDF files typically start as another document type, such as a Microsoft Word document, and are then exported or saved as a PDF. There are then two files containing the same content - a Word document (.docx) and a PDF (.pdf). Many files found on the web are PDFs. They are used for many reasons:
PDF files typically start as another document type, such as a Microsoft Word document, and are then exported as PDFs. Ideally, document accessibility should begin there. Many things can be done to support accessibility in the source file, such as adding alternative text for images; defining structural headings, lists, and data tables; and providing a document language.
Whether or not you have access to a source file, Adobe Acrobat can be used to assist with PDF accessibility.
PDF Accessibility Overview
Learn the characteristics of accessible PDF files, such as searchable text, navigational aids, and a proper title.
Acrobat Pro Accessibility Checker
User Acrobat's built-in checker, which provides a guided, step-by-step approach to fix accessibility issues.