About accessible pdfs – Adobe Acrobat XI User Manual
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Accessibility, tags, and reflow
Last updated 1/14/2015
For more information about accessibility features, see these resources:
• Acrobat accessibility, overview, new features, and FAQ:
• Information and news about accessibility in Adobe products:
• Creating accessible PDF document
• General accessibility tips:
About accessible PDFs
Accessible PDFs have the following characteristics.
Searchable text
A document that consists of scanned images of text is inherently inaccessible because the content of the document is
images, not searchable text. Assistive software cannot read or extract the words, users cannot select or edit the text, and
you cannot manipulate the PDF for accessibility. Convert the scanned images of text to searchable text using optical
character recognition (OCR) before you can use other accessibility features with the document.
Alternate text descriptions (Acrobat Pro)
Screen readers cannot read document features such as images and interactive form fields unless they have associated
alternate text. Screen readers can read web links; however, you can provide more meaningful descriptions as alternate
text. Alternate text and tool tips can aid many users, including users with learning disabilities.
Fonts that allow characters to be extracted to text (Acrobat Pro)
The fonts in an accessible PDF must contain enough information for Acrobat to extract all of the characters to text for
purposes other than displaying text on the screen. Acrobat extracts characters to Unicode text when you read a PDF
with a screen reader or the Read Out Loud feature. Acrobat also extracts characters to Unicode when you save as text
for a braille printer. This extraction fails if Acrobat cannot determine how to map the font to Unicode characters.
Reading order and document structure tags (Acrobat Pro)
To read a document’s text and present it in a way that makes sense to the user, a screen reader or other text-to-speech
tool requires a structured document. Document structure tags in a PDF define the reading order and identify headings,
paragraphs, sections, tables, and other page elements.
Interactive form fields (Acrobat Pro)
Some PDFs contain forms that a person is to fill out using a computer. To be accessible, form fields must be interactive
to let the user enter values into the form fields.
Navigational aids (Acrobat Pro)
Navigational aids in a PDF include links, bookmarks, headings, table of contents, and preset tab order for form fields.
Navigational aids assist users in understanding the document without reading completely through it. Bookmarks are
especially useful and can be created from document headings.
Document language (Acrobat Pro)
Specifying the document language in a PDF enables some screen readers to switch to the appropriate language.
Security that doesn’t interfere with assistive software (Acrobat Pro)