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Grackle for Google Docs – How It Works

Document Accessibility Made Easy

Grackle Docs drop down menu

Grackle Docs is an add-on that runs in Google Docs.

You can install Grackle Docs here.

When opened, it scans the current document for accessibility issues.

When the scan finishes, Grackle Docs arranges the document’s elements and structures into categories.

  • Document
  • Images
  • Headings
  • Tables
  • Landmarks
  • Content

These categories can be seen in the user interface on the right side of the screen.

Elements in each are marked as either accessible or inaccessible. Changes are made by selecting and editing these elements in these categories. For example, a table does not have the header row specified with a tag. When an element is changed with Grackle Docs, it edits the tags for that element in the document. This edit is immediate and no saving is required.



Document properties are primarily useful when exporting to tagged, GrackleDocs PDF

  • Document Title
  • Document Language
Document section of Grackle
Image section of Grackle


Grackle checks for compliance against several accessibility requirements.

Also called “alt tags” and “alt descriptions,” alt text is the written copy that should appear with an image, drawing or equation on a document to help screen-reading tools describe images.

  • Images have alt-text (or are marked as artifacts)
  • Drawings have alt-text
  • Equations have alt-text
  • Image size – This is not an accessibility check but does help with resulting file sizes and some limitations set by Google!

Grackle Docs also flags images that appear to be using their filename as an alt-tag, rather than robust descriptions.


Grackle checks against three accessibility requirements related to headings.

  • Headings are present in the document
  • A single ‘Heading 1’ should be used – This is a warning only
  • Headings are nested correctly

Grackle counts both the highest heading value reached and the number of paragraphs with heading styles.

Pro-tip: Headings should follow a logical order. An H2 heading should follow H1, and should be followed by H3.

Heading section of Grackle
Table section of Grackle


Tables are common in corporate and academic documents and are commonly inaccessible.

They pose a special challenge for screen readers because they present textual or numerical data to be easily referenced visually.

A Google Doc does not have the concept of a datas table and represeents a table as a grid without mark up. Once Grackled, this grid turns into a fully functioning, marked up table within PDF.

  • Tables must be tagged or marked as layout
  • Merged cells are not recommended – This is a warning only
  • Empty cells are not recommended – This is a warning only

Grackle visualizes the fields in each table to help the user tag headers and columns.


Grackle checks for three features that help accessibility users recognize and transit the document.

  • Lists are used where appropriate
  • Footnotes have IDs and Alts.
  • Headers and Footers are present and descriptive
Landmarks section of Grackle
Contents section of Grackle


Grackle scans against and helps resolve five (7) content-related accessibility issues.

  • Unsupported content
    • e.g. Horizontal line function does not pass through the Google API to Grackle
  • Colors should be high contrast
  • Fine print should be avoided
  • All caps text should be avoided
  • Text should aligned horizontally
  • Lengthy paragraphs should be avoided
  • Links should be informative

Take a Look at the demo below and see, it's a snap!