Business
Jobs
  • About Us
  • Solutions
    • Job Postings
      Post your job and receive qualified candidates in 48h.
    • Candidate Assessments
      500+ technical and psychological tests, plus anti-fraud.
    • Headhunting
      Tailor-made executive search from start to finish.
    • Payroll + EOR
      Payroll dispersal and EOR across 15+ LATAM countries.
  • Pricing
  • Jobs

0

378
Views
nextjs: Warning: Prop `className` did not match. Server: "x" Client: "y"

This is my code:

export default function Nav() {
    const { userLogin } = useUser()
    console.log(userLogin)
    
    return (
        <nav className={styles.nav}>
            {!userLogin ? (
                <Link href={"/login"}><a className={`${styles.top}`}></a></Link>
            ) : (
                <Link href={"/profile"}><a className={`${styles.userLogged}`}></a></Link>
            )}
        </nav>
    )
}

And this is useUser:

export default function useUser(){
    var userLogin = false

    const cookies = parseCookies()
    if (cookies.token) {
        userLogin = true
    }

    return { userLogin }
}

So, if userLogin is false, everything is OK.

But if userLogin is true I get this error:

Warning: Prop `className` did not match. Server: "x" Client: "y"

This error show when I use cookies.

I don't want to use next/dynamic. because dynamic reload component again on click.

over 4 years ago · Santiago Trujillo
1 answers
Answer question

0

If parseCookies happen only client-side, aka, uses document then next will have different HTML from the client, this happens to me with localStorage because I'm using window.

But because you are using cookies you can get them from getInitialProps's req argument:

App.getInitialProps = async ({ ctx }) => {
  const { req } = ctx;

  const cookies = parseCookies(req ? req.headers.cookie : document.cookie);

  return {
    pageProps:  { cookies }
  };
};

If you are using nookies they have a cool integration with Next.js which allows you to pass the ctx as the first argument like so: const cookies = parseCookies(ctx) and ctx will come from getInitialProps or getServerSideProps

see https://github.com/maticzav/nookies/blob/c4b1ca461e7b04877d295cb740fa8cbc1db2ad36/packages/nookies/src/index.ts?_pjax=%23js-repo-pjax-container%2C%20div%5Bitemtype%3D%22http%3A%2F%2Fschema.org%2FSoftwareSourceCode%22%5D%20main%2C%20%5Bdata-pjax-container%5D#L15

over 4 years ago · Santiago Trujillo Report
Answer question
Find remote jobs

Discover the new way to find a job!

Top jobs
Top job categories
Business
Post vacancy Pricing Sales
Legal
Terms and conditions Privacy policy
© 2026 PeakU Inc. All Rights Reserved.
Andres GPT
Show me some job opportunities
There's an error!