A tree hydrated but some attributes of the server rendered HTML didn't match the client properties.

[Ashvith10]

Link to the code that reproduces this issue

https://github.com/vercel/next.js/tree/canary/examples/with-typescript

To Reproduce

1. Start the application with npm run dev
2. Go to http://localhost:3000/
3. Get greeted by hydration error

Current vs. Expected behavior

Current behavior:

Expected behaviour:

No hydration error (More details in "Additional context")

Provide environment information

$ npx next info
/gnu/store/jlqbjxk51bdq5w7wlnbmwxm1j0pnllpx-bash-minimal-5.1.16/bin/sh: line 1: yarn: command not found
/gnu/store/jlqbjxk51bdq5w7wlnbmwxm1j0pnllpx-bash-minimal-5.1.16/bin/sh: line 1: pnpm: command not found

Operating System:
  Platform: linux
  Arch: x64
  Version: #1 SMP PREEMPT_DYNAMIC 1
  Available memory (MB): 15877
  Available CPU cores: 8
Binaries:
  Node: 20.18.1
  npm: 10.8.2
  Yarn: N/A
  pnpm: N/A
Relevant Packages:
  next: 15.1.6 // Latest available version is detected (15.1.6).
  eslint-config-next: 15.1.6
  react: 19.0.0
  react-dom: 19.0.0
  typescript: 5.7.3
Next.js Config:
  output: N/A

Which area(s) are affected? (Select all that apply)

Not sure

Which stage(s) are affected? (Select all that apply)

next dev (local)

Additional context

This issue disappears once https://localhost:3000 is added to the "Not invert listed" column in the Dark Reader extension, inside the "Site list" tab. This issue was created to document one of the many reasons for failure in hydration.

[github-actions]

We could not detect a valid reproduction link. Make sure to follow the bug report template carefully.

Why was this issue closed?

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What should I do?

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My repository is private and cannot make it public

In most cases, a private repo will not be a sufficient minimal reproduction, as this codebase might contain a lot of unrelated parts that would make our investigation take longer. Please do not make it public. Instead, create a new repository using the templates above, adding the relevant code to reproduce the issue. Common things to look out for:

• Remove any code that is not related to the issue. (pages, API routes, components, etc.)
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• If the issue is not related to a monorepo specifically, try to reproduce the issue without a complex monorepo setup

I did not open this issue, but it is relevant to me, what can I do to help?

Anyone experiencing the same issue is welcome to provide a minimal reproduction following the above steps by opening a new issue.

I think my reproduction is good enough, why aren't you looking into it quickly?

We look into every Next.js issue and constantly monitor open issues for new comments.

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Useful Resources

• How to Contribute to Open Source (Next.js)
• How to create a Minimal, Complete, and Verifiable example
• Reporting a Next.js bug
• Next.js Triaging issues