If you’ve written React code in any server-rendered framework, you’ve almost certainly gotten a hydration error. These look like: Text content does not match server-rendered HTML or Error: Hydration failed because the initial UI does not match what was rendered on the server And after the first time you see this, you quickly realize you can just dismiss it and move on... kind of odd for an error message that’s so in-your-face (later on, we’ll see that you might not want to dismiss them entir