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Text content does not match server-rendered HTML

Why This Error Occurred​

While rendering your application, there was a difference between the React tree that was pre-rendered from the server and the React tree that was rendered during the first render in the browser (hydration).

Hydration is when React converts the pre-rendered HTML from the server into a fully interactive application by attaching event handlers.

Common Causes​

Hydration errors can occur from:

  1. Incorrect nesting of HTML tags
    1. <p> nested in another <p> tag
    2. <div> nested in a <p> tag
    3. <ul> or <ol> nested in a <p> tag
    4. Interactive Content cannot be nested (<a> nested in a <a> tag, <button> nested in a <button> tag, etc.)
  2. Using checks like typeof window !== 'undefined' in your rendering logic
  3. Using browser-only APIs like window or localStorage in your rendering logic
  4. Using time-dependent APIs such as the Date() constructor in your rendering logic
  5. Browser extensions modifying the HTML
  6. Incorrectly configured CSS-in-JS libraries
    1. Ensure your code is following our official examples
  7. Incorrectly configured Edge/CDN that attempts to modify the html response, such as Cloudflare Auto Minify

Possible Ways to Fix It​

The following strategies can help address this error:

Solution 1: Using useEffect to run on the client only​

Ensure that the component renders the same content server-side as it does during the initial client-side render to prevent a hydration mismatch. You can intentionally render different content on the client with the useEffect hook.

import { useState, useEffect } from 'react'

export default function App() {
  const [isClient, setIsClient] = useState(false)

  useEffect(() => {
    setIsClient(true)
  }, [])

  return <h1>{isClient ? 'This is never prerendered' : 'Prerendered'}</h1>
}

During React hydration, useEffect is called. This means browser APIs like window are available to use without hydration mismatches.

Solution 2: Disabling SSR on specific components​

Next.js allows you to disable prerendering on specific components, which can prevent hydration mismatches.

import dynamic from 'next/dynamic'

const NoSSR = dynamic(() => import('../components/no-ssr'), { ssr: false })

export default function Page() {
  return (
    <div>
      <NoSSR />
    </div>
  )
}

Solution 3: Using suppressHydrationWarning​

Sometimes content will inevitably differ between the server and client, such as a timestamp. You can silence the hydration mismatch warning by adding suppressHydrationWarning={true} to the element.

<time datetime="2016-10-25" suppressHydrationWarning />

Common iOS issues​

iOS attempts to detect phone numbers, email addresses, and other data in text content and convert them into links, leading to hydration mismatches.

This can be disabled with the following meta tag:

<meta
  name="format-detection"
  content="telephone=no, date=no, email=no, address=no"
/>