SSE (Server Sent Events) causes lighthouse to timeout

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FAQ

• Yes, my issue is not about variability or throttling.
• Yes, my issue is not about a specific accessibility audit (file with axe-core instead).
• Yes, my issue is not answered by other FAQs.

URL

https://gravel-gilded-shirt.glitch.me/sse.html

What happened?

Quick backstory, was using WebSockets on my website for omnidirectional data sending and saw lighthouse saying WebSockets causes issues with bfcache, no issue there.

Changed my implementation to SSE as they're made for one direction data sending anyway, now it causes lighthouse to wait until the (set?) timeout finishes, dropping a warning message

"The page loaded too slowly to finish within the time limit. Results may be incomplete."

What did you expect?

Proper implementation of SSE, especially since using WebSockets causes a fail under performance in lighthouse which may lead developers to using SSE.

What have you tried?

How were you running Lighthouse?

Chrome DevTools, web.dev

Lighthouse Version

12.0.0

Chrome Version

126.0.6478.251 (Official Build) (64-bit)

Node Version

No response

OS

Windows

Relevant log output

No response

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Unrelated note, I notice when running test from pagespeed.web.dev, it fails to connect to both WebSockets and SSE endpoints, I assume its intentional though.