Summary

MDN's new "ai explain" button on code blocks generates human-like text that may be correct by happenstance, or may contain convincing falsehoods. this is a strange decision for a technical reference.

URL

https://developer.mozilla.org/en-US/docs/Web/CSS/grid

Reproduction steps

as soon as i heard about this, i visited the first MDN article in my address bar history (for the grid property), hit "ai explain" on the first code block encountered (the syntax summary), and received the following information:

grid: "a" 100px "b" 1fr;: This value sets the grid template to have two rows and two columns. The first row has a height of 100 pixels and the second row has a height of 1 fraction unit (1fr). The columns are named "a" and "b".

which is deeply but subtly incorrect — this creates only one column (more would require a slash), and the quoted strings are names of areas, not columns. but it's believable, and it's interwoven with explanations of other property values that are correct. this is especially bad since grid is a complex property with a complex shorthand syntax — exactly the sort of thing someone might want to hit an "explain" button on.

the generated text appears to be unreviewed, unreliable, unaccountable, and even unable to be corrected. at least if the text were baked into a repository, it could be subject to human oversight and pull requests, but as best i can tell it's just in a cache somewhere? it seems like this feature was conceived, developed, and deployed without even considering that an LLM might generate convincing gibberish, even though that's precisely what they're designed to do.

and far from disclaiming that the responses might be confidently wrong, you have called it a "trusted companion". i don't understand this.

Expected behavior

i would like MDN to contain correct information

Actual behavior

MDN has generated a convincing-sounding lie and there is no apparent process for correcting it

Device

Desktop

Browser

Firefox

Browser version

Stable

Operating system

Linux

Screenshot

No response

Anything else?

No response

Validations

• I have read the Community Participation Guidelines.
• I have verified that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• I have checked that this is a concrete bug. For Q&A open a GitHub Discussion.