Summary
There is a built-in delay of about 300 ms, controlled by FALLBACK_THROTTLE_MS, before Suspense content appears on the page if the promise is unresolved, but this is not documented.
Page
https://react.dev/reference/react/Suspense
Details
There have been several issues opened in the React repo regarding a 300ms delay in Suspense.
This is a design decision that should be called out so users can expect it as a caveat.
Summary
There is a built-in delay of about 300 ms, controlled by FALLBACK_THROTTLE_MS, before Suspense content appears on the page if the promise is unresolved, but this is not documented.
Page
https://react.dev/reference/react/Suspense
Details
There have been several issues opened in the React repo regarding a 300ms delay in Suspense.
FALLBACK_THROTTLE_MSslows tests down significantly - could it be configurable? react/react#30408FALLBACK_THROTTLE_MS) kicks in too often react/react#31819This is a design decision that should be called out so users can expect it as a caveat.