`kernelUnitLength` is deprecated

[yinhx3]

MDN URL

https://developer.mozilla.org/en-US/docs/Web/SVG/Reference/Attribute/kernelUnitLength

What specific section or headline is this issue about?

No response

What information was incorrect, unhelpful, or incomplete?

According to the specification, this attribute has been deprecated in <feConvolveMatrix> and <feDiffuseLighting>:

<feConvolveMatrix> Note, <feDiffuseLighting> Note
Note: This attribute is deprecated and will be removed. It does not provide a reliable way to create platform-independent results. Future versions of this specification will cover this use case.

(<feSpecularLighting> doesn't has this note)

I ran simple tests, and it seems that this attribute has no effect in Chrome, even in <feSpecularLighting>. (To be fair, I don’t fully understand its intended purpose, so it’s possible I used it incorrectly.)

What did you expect to see?

If the attribute is indeed deprecated, the documentation should explicitly mark it as such.

Do you have any supporting links, references, or citations?

No response

Do you have anything more you want to share?

No response

MDN metadata

Page report details

• Folder: en-us/web/svg/reference/attribute/kernelunitlength
• MDN URL: https://developer.mozilla.org/en-US/docs/Web/SVG/Reference/Attribute/kernelUnitLength
• GitHub URL: https://github.com/mdn/content/blob/main/files/en-us/web/svg/reference/attribute/kernelunitlength/index.md
• Last commit: mdn/content@d22284c
• Document last modified: 2025-07-12T03:04:39.000Z

[Josh-Cena]

This first needs to be marked in BCD as deprecated for all three elements, and then we can add BCD keys for this page and the status will automatically propagate.