Eventually, we’ll get Webstandards.TO back up and running per se (rather than my paltry placeholder). We might have a log or something. In the interim, a mailing-list posting of mine has definitive information that everyone is overlooking, so I’m putting it in a second place: Here.

Do screen readers work better with valid HTML?

The answer is yes.

Is validity an accessibility issue?

The need to use technologies according to specification is a broader issue than most of the guidelines in WCAG. In issue 572 as well as on the mailinglist, people have wondered whether this guideline should be in WCAG because they feel it’s not about accessibility. Others have argued that valid markup increases the chances of correct rendering of the content which directly benefits accessibility.

I canvassed the makers of Two Leading Screen Readers. Take a wild guess as to which two.

[Product 1] does tend to behave better with valid code because the browser behaves better with valid code. Take, for example, tables. Invalid table code may cause tables to be rendered incorrectly, thereby causing [Product 1] to read them incorrectly. Since we get information about the page directly from the DOM, if the DOM is invalid, the information we’re presenting to the user has the potential to be invalid as well. Ideally, if the DOM is correct, we will be correct.


The developer who handles the HTML code states that valid HTML is very important for screen readers as working around it is one of our greatest hassles.

As for the specific elements and attributes supported by [Product 2], I will have a comprehensive list available by mid-February. Our documentation team is working on some training materials for making accessible web sites and this will be a portion of their effort.

(Still waiting for that one. I sent in another request.)

The foregoing posting appeared on Joe Clark’s personal Weblog on 2004.05.13 16:48. This presentation was designed for printing and omits components that make sense only onscreen. (If you are seeing this on a screen, then the page stylesheet was not loaded or not loaded properly.) The permanent link is:

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None. I quit.

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