WAVE extension detecting more errors as compared to axe-core extension

[Shivam93937]

Product

axe Extension

Product Version

Extension: v4.110.0 axe-core: v4.10.3

Latest Version

• I have tested the issue with the latest version of the product

Issue Description

Expectation

I expected axe core to find all the errors in static analysis.
WAVE extension points out more images with missing alt text.

Actual

Axe-core extension does not point out all the images with alt-text, missing labels and empty buttons.

How to Reproduce

Go to play.geforcenow.com
Run WAVE extension and Axe-core extension on the page.
Observe the differences in results between both.

Additional context

[WilcoFiers]

@Shivam93937 Can you give specific examples of things WAVE fails that you would expect axe to fail?

Speaking generally, this doesn't surprise me. It's a feature, not a bug.

Axe-core is built to avoid failing things that aren't true accessibility failures. For example, that means axe won't fail hidden images. Other tools may fail them, making the assumption that a hidden image will be a visible at some point. That makes finding the problem easier - but it also means that if the images is never visible those tools fail the image even though it isn't a true accessibility problem.

Another way in which axe-core avoids failing things that aren't true issues is that axe is more permissive of sub-optimal solutions. It's generally not a good practice to use aria-label on an image for example. There are accessibility tools that will fail images that do this. Axe allows this because it does work in assistive technologies.

Lastly axe-core also avoid things that are generally considered bad practices, but may end up being minimally sufficient. A common example is using file names as alt attributes. A lot of tools fail this. Axe-core doesn't because while this is never a good idea, an alt of "penguins.jpg" does tell you what's on the image. It may be sufficient, even if it isn't good.