Suppress Expected Hydration Mismatches
In SSR frameworks (e.g., Next.js), some values are intentionally different on server vs client (random IDs, dates, locale/timezone formatting). For these *expected* mismatches, wrap the dynamic text in an element with suppressHydrationWarning to prevent noisy warnings. Do not use this to hide real bugs. Don’t overuse it.
Incorrect (known mismatch warnings):
function Timestamp() {
return <span>{new Date().toLocaleString()}</span>
}Correct (suppress expected mismatch only):
function Timestamp() {
return (
<span suppressHydrationWarning>
{new Date().toLocaleString()}
</span>
)
}