Experimental HTTPS in NextJS 16.2, ERR_EMPTY_RESPONSE

[Fred638]

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Question

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I have configured my application to use https; "dev": "next dev --experimental-https, installed a self-signed certificate. All good, however, when logging in or logging off the page shows, "... localhost didn't send any data. ERR_EMPTY_RESPONSE."

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[prashantkoirala465]

This sounds like the HTTPS setup itself is working, but something is breaking when the authentication flow triggers a request or redirect.

A few things I'd check:

• Make sure your auth callback/redirect URLs are using https://localhost instead of http://localhost. Some authentication libraries will fail silently if the callback URL doesn't match.
• Check whether your cookies are configured correctly. If you're using secure cookies, they need to be sent over HTTPS only, and a mismatch between HTTP/HTTPS can cause login sessions to fail.
• Look at the browser developer tools:
  • Network tab → check which request returns ERR_EMPTY_RESPONSE
  • Console tab → look for certificate, CORS, or cookie errors
• Check your terminal output while reproducing the issue. Next.js usually logs if the server crashes or an API route throws an error.

Since the page loads normally over HTTPS and only fails during login/logout, I'd suspect an API route, authentication callback, or middleware issue rather than the experimental HTTPS feature itself.

Which authentication setup are you using (NextAuth/Auth.js, custom API routes, Clerk, Supabase, etc.)? That would help narrow it down.

[Fred638]

Thanks for pointing out. I'll check the mentioned. I am using NextAuth/Auth.js.

[monmoymondol]

Hey Fred638,

Looks like your HTTPS setup itself is fine — the error usually happens when something in the login or logout redirect breaks before the server sends a response.

Try these quick checks:
• Make sure your auth callback URLs use https://localhost, not http://localhost.
• If you’re using secure cookies, they must be sent only over HTTPS — a mismatch can cause empty responses.
• Open your browser’s Network and Console tabs to see if any requests fail or show CORS/certificate errors.
• Check your terminal logs while reproducing the issue — Next.js often prints the exact route or error causing the blank page.

If everything looks correct, try running without --experimental-https and use a local proxy like mkcert or Caddy to confirm whether the issue is in Next.js’s experimental HTTPS layer.

It’s usually just a redirect or cookie config mismatch — once those line up, the error should disappear.