ACE
accessibility
checker

What is ACE?

• EPUB checking tool by DAISY consortium
• reports accessibility issues
• version 1.0 released on 29 January 2018

Before you start with ACE…

Check your EPUB with EPUBcheck first!
An invalid EPUB is by no means accessible.

Common issues

• current version of accessibility guidelines not implemented yet
• missing accessibility metadata
• Untitled BODY
• Element has no ARIA role matching its epub:type
• alternative texts for equations and images

ACE in transpect

• XProc wrapper for ACE on command line
• converts JSON report to Schematron SVRL
• included in HTML report

ACE in transpect

• ACE check is only started when EPUB is valid
• messages are included in EPUBcheck category
• message severity can be overwritten (e.g. test mode)

Issues

• report is a summary of all ACE messages
• messages do not point to original error location
• ACE seems pretty unstable for invalid EPUBs and “magically” crashes