Hydration error while installing NextJS 15

#webdev #nextjs #javascript #react

After creating a new next 15 project and running the server

npm run dev

if you see these error in your development server:

Hydration failed because the server rendered HTML didn't match the client. As a result this tree will be regenerated on the client. This can happen if a SSR-ed Client Component used

A server/client branch if (typeof window !== 'undefined').
Variable input such as Date.now() or Math.random() which changes each time it's called.
Date formatting in a user's locale which doesn't match the server.
External changing data without sending a snapshot of it along with the HTML.
Invalid HTML tag nesting.

It can also happen if the client has a browser extension installed which messes with the HTML before React loaded.

See more info here: https://nextjs.org/docs/messages/react-hydration-error

Here is the solve

use this suppressHydrationWarning attribute in your layout.tsx file

return (
    <html lang='en' suppressHydrationWarning>

if this doesn't solve your problem, then So far these are the mentioned extensions that cause hydration errors I have seen here. You guys can add up further names to gather them in a single place to help other fellow devs:

1 - ColorZilla

2 - Wappalyzer

3 - Urban VPN

4 - LastPass

5 - Hacker Vision

6 - WhatFont

7 - Video Speed Controller for HTML videos

8 - Glot

9 - AI Grammar Checker & Paraphraser – LanguageTool

10 - Grammarly

11 - Invert

12 - Dashlane

Happy Coding :)

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