How do I integrate Prerender with Cloudflare Workers?

TL;DR

Connect Prerender to your Cloudflare-proxied website by deploying a Workers script that intercepts crawler requests and routes them through Prerender's rendering solution. You'll need Cloudflare Worker Admin access and your Prerender token. Setup takes about 15–20 minutes, and the integration starts working within a couple of minutes of final deployment.

Step 1: Open your Prerender dashboard and copy your token

1. Log in to your Prerender dashboard.
2. Go to Security and Access and copy your Prerender token.
   
   

Step 2: Confirm Cloudflare is proxying your domain

This integration only works when Cloudflare is acting as a proxy for your domain — not just as a DNS provider.

1. Open your Cloudflare dashboard and go to DNS > Records for your domain.
2. Check that your A record or CNAME has the Proxied status — the orange cloud icon.

Step 3: Allow AI crawlers in Cloudflare

Cloudflare automatically blocks AI training crawlers on newly added domains. If you want AI crawlers to discover and index your content through Prerender, you must explicitly allow them.

1. From the Account Home menu, select your domain.
2. On the Overview page, find Control AI crawlers and set it to allow.

Step 4: Create a new Cloudflare Worker

1. In your Cloudflare dashboard, go to Compute and AI > Workers & Pages.
2. Click Create Application and select Start with Hello World!
3. Name the worker (for example, prerender-worker) and click Deploy.
   
4. Click Edit Code in the top right.
5. Copy the Prerender worker source code from GitHub, paste it into the editor, and replace the default Hello World code entirely.
   
6. Do not deploy yet — continue to Step 5 first.

Step 5: Configure the worker route

1. Go to your worker's Settings tab and select Domains & Routes.
2. Add a route that matches the domain where you want Prerender to run. Use the patterns below:
   

   Website	Route pattern
   example.com	example.com/*
   www.example.com	www.example.com/*
   Both with and without www	*example.com/*
   Any subdomain	*.example.com/*
   Specific subdomain	blog.example.com/*

3. Set Failure mode to Fail open (proceed).
   
4. Save the settings.

Step 6: Add your Prerender token as an environment variable

1. Still in Settings, go to Variables and Secrets.
   
2. Add a new variable with these values:
   • Type: Text
   • Variable name: PRERENDER_TOKEN
   • Value: paste the token you copied in Step 1
     
     
     
     
3. Save the variable.

Step 7: Deploy the worker

Click Deploy to push the worker live.   

Step 8: Verify your integration

Before you consider the integration complete, confirm that Prerender is correctly intercepting crawler requests and serving rendered HTML.

Follow the steps in How do I verify my Prerender integration? to test your setup.

If you don't see Prerender headers or IDs in the verification output, the integration is not active. Check that your worker route pattern matches the URL you're testing and that the PRERENDER_TOKEN variable is saved correctly in your worker settings.

If you see the message "Prerender Integration Not Detected," follow the steps in What should I do if I receive a "Prerender Integration Not Detected" error? to resolve it.

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