FrontendIntermediate
Hydration
Pronunciationhy-DRAY-shun
Definition
The step where the browser attaches JavaScript to HTML that the server already sent, so the page becomes interactive.
Where you hear it
Next.js and React errors like "hydration mismatch".
Examples
We got a hydration error because the server and client rendered different text.
The page is visible quickly, then hydration makes the buttons work.
Common mistake
Using values like Date.now() or random numbers while rendering. The server and browser get different results.