[BUG] Page router next/head component not working for SSR pages

[hcentelles]

Describe the bug

When the Page Router next/head component is used on SSG or dynamic (SSR) pages the html that came from the server did not have the meta tags that the component should add.

The meta tags are added later (on hydration phase I suppose), if I inspect the page in the devtools Elements tab I can verify it.

On static pages it works ok.

Steps to reproduce

1. Clone this reproduction repo created with the npm create cloudflare@latest -- my-next-app --framework=next --platform=workers command: https://github.com/hcentelles/my-next-app
2. Install deps: npm i
3. Run the app with the "native" nextjs server: npm run build && npm run start
4. Download the html of the SSG example page: curl -o ssg-nextjs.html http://localhost:3000/ssg
5. Kill the nextjs server Ctrl+C
6. Run the app with the opennext preview command: npm run preview
7. Download the html of the SSG example page: curl -o ssg-opennext.html http://localhost:8787/ssg
8. Compare both files to verify that in ssg-nextjs.html exist the <title data-next-head="">SSG Example</title> tag but in ssg-opennext.html do not exist.

Expected behavior

I would expect the <title data-next-head="">SSG Example</title> tag to be in ssg-opennext.html too.

@opennextjs/cloudflare version

1.0.0-beta.2

Wrangler version

4.10.0

next info output

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 24.3.0: Thu Jan  2 20:24:23 PST 2025; root:xnu-11215.81.4~3/RELEASE_ARM64_T8122
  Available memory (MB): 24576
  Available CPU cores: 8
Binaries:
  Node: 20.12.1
  npm: 10.5.0
  Yarn: 1.22.19
  pnpm: N/A
Relevant Packages:
  next: 15.2.5 // There is a newer version (15.3.0) available, upgrade recommended! 
  eslint-config-next: N/A
  react: 19.1.0
  react-dom: 19.1.0
  typescript: N/A
Next.js Config:
  output: N/A
 ⚠ There is a newer version (15.3.0) available, upgrade recommended! 
   Please try the latest canary version (`npm install next@canary`) to confirm the issue still exists before creating a new issue.
   Read more - https://nextjs.org/docs/messages/opening-an-issue

Additional context

No response

[vicb]

You need to configure the cache, see the comments/links in open-next.config.ts

For ex, it works with:

import { defineCloudflareConfig } from "@opennextjs/cloudflare";
import incrementalCache from "@opennextjs/cloudflare/overrides/incremental-cache/static-assets-incremental-cache";

export default defineCloudflareConfig({
  // Uncomment to enable R2 cache,
  // It should be imported as:
  // `import r2IncrementalCache from "@opennextjs/cloudflare/overrides/incremental-cache/r2-incremental-cache";`
  // See https://opennext.js.org/cloudflare/caching for more details
  incrementalCache
});

Check https://opennext.js.org/cloudflare/caching for more details

[hcentelles]

@vicb thanks for your answer, I try your solution and it works fine for SSG. But for dynamics pages (SSR) do not work. I updated the reproduction repo with your solution.

Here the steps to reproduce the bug with SSR:

1. Clone this reproduction repo created with the npm create cloudflare@latest -- my-next-app --framework=next --platform=workers command: https://github.com/hcentelles/my-next-app
2. Install deps: npm i
3. Run the app with the "native" nextjs server: npm run build && npm run start
4. Download the html of the SSR example page: curl -o ssr-nextjs.html http://localhost:3000/ssr
5. Kill the nextjs server Ctrl+C
6. Run the app with the opennext preview command: npm run preview
7. Download the html of the SSR example page: curl -o ssr-opennext.html http://localhost:8787/ssr
8. Compare both files to verify that in ssr-nextjs.html exist the <title data-next-head="">SSR Example</title> tag but in ssr-opennext.html do not exist.

[vicb]

@conico974 Do you have any idea of where the difference can come from in SSR?

[conico974]

Honestly I don't know, I'll have to take a look. Only thing I can think of would be that somehow there is an issue with file tracing

[hcentelles]

@vicb @conico974 thanks for your answers . Do you think it's OK to reopen this issue changing the title to reflect it's related to SSR or should I open a new one?

[conico974]

I've tested your repro, the <title> is included, it's just that for some reason it seems to don't add any attributes to the html <title> tag.
It's probably not a big deal, but something that should be looked into further.
My guess is that something either in esbuild or wrangler itself is causing some issue with the title jsx

[hcentelles]

@conico974 just to be clear, it's not just title, any tag I place as children of next/head do not show in the html that comes from the server. Ex here

In my case there is were I place all the SEO related meta tags of each page, title, description, open graph tags, etc. That's not working now with page router SSR pages.

[hcentelles]

@vicb @conico974 I was looking into this to see if I can help fixing this bug, because is the only thing blocking me to migrate my app from Vercel to Cloudflare, I didn’t get very far. But I gave the whole code of opennextjs-cloudflare and opennextjs-aws to Gemini 2.5 Pro, asking it to find the source of the bug, and this is the output. Maybe it can help you, or it could be garbage, honestly I don't know.

• response 1
• response 2

[conico974]

@hcentelles The AI response is nonsense (as i expected to be fair).
I've took another quick look at it, you're right the ssr response does not contain the <title> tag, it gets added afterward during CSR it seems.

The issue does not happen in aws, it works just fine there (or locally). There is likely something during bundling that is causing the issue. If i had to guess, i'd say that _document and the ssr page itself are using 2 different versions of the <Head> provider for some reason (thus causing the issue)