Description

Browsers should investigate and work towards generating consistent accessibility tries from the same DOM + CSS.

Rationale

All browsers produce subtly different accessibility trees for the same DOM + CSS. Some examples:

• CSS display property impacts the a11y tree inconsistently

• https://www.powermapper.com/tests/screen-readers/aria/

• https://a11ysupport.io/

• For something more hands-on, on a macOS device, using VoiceOver to interact with this W3C datepicker example gives slightly different results between Chrome, Safari, and Firefox:

  Chrome:
  Date, dialog pop up, Menu pop-up combobox
  (date format: mm/dd/yyyy)
  Choose date, dialog with 8 items, Entering October 2022 table. 12, October 2022, table, 7 columns, 7 rows

  Safari:
  Date, dialog pop up, Menu pop-up combobox
  (date format: mm/dd/yyyy)
  Choose date, web dialog, with 8 items 12, Entering October 2022. 12, October 2022 table, 7 columns, 7 rows

  Firefox:
  Date, combobox
  (date format: mm/dd/yyyy)
  Choose date, web dialog, with 8 items 12, Entering October 2022. 12, October 2022 table, 7 columns, 7 rows

While some differences are mostly innocuous ("dialog" vs "web dialog"), having any sort of standardization or interop testing would be a huge boon to all web developers trying to build accessible experiences.

Investigation Roadmap

See #211 (comment)

(Description updated by @foolip Oct 31.)