Verify Your Prerender Integration

Overview

Once you've integrated Prerender.io into your tech stack, it's important to verify that it works as expected—especially that bots are receiving pre-rendered HTML as expected.

Method 1: Chrome DevTools

Simulate a bot visit manually and inspect response headers.

Method 2: Prerender App

Run a one-click domain check from inside Prerender.

Method 1: Chrome DevTools

This guide walks you through how to simulate a crawler visit and confirm that your Prerender integration is responding correctly. We recommend using Google Chrome for this process, though you can adapt the same steps in other browsers with developer tools.

Detailed Explanation / How It Works

The Prerender integration works by detecting bots through their user agent and serving them a static, pre-rendered HTML version of your page. To verify this behavior:

You simulate a bot visit by changing your browser’s user agent in DevTools.
You inspect the network response to confirm whether it’s coming from Prerender.
If correct, the HTML will be static, and the response headers will include x-prerender-request-id.

Steps

1. Open the Page You Want to Test

Navigate to the URL you want to test.

2. Open Developer Tools

Windows: Press Ctrl + Shift + J
Mac: Press Option + ⌘ + J

3. Show Network Conditions Panel

Windows: Press Ctrl + Shift + P
Mac: Press Command + Shift + P
Type “Show Network Conditions” and select it

4. Modify the User Agent

In the Network Conditions tab, uncheck “Use browser default”
Select Googlebot from the dropdown list
If your integration uses a custom allowlist, choose a bot included in your config

5. Reload and Inspect the Response

Refresh the page to simulate a prerendered crawler visit
Switch to the Network tab in DevTools
Select the main document (usually the URL you visited)
Check for the presence of x-prerender-request-id in the response headers

How to Know When You’re Done

If you see the x-prerender-request-id header after simulating a crawler visit, it confirms that Prerender is working correctly, and serving cached HTML to bots.

Note: If the header doesn't appear right away, wait a few minutes and refresh. Changes can take a little time to propagate. Once validated, new entries will appear in the Prerender app under CDN Analytics.

Bot Validation Scenario

Some sites block simulated bot requests. If you're not seeing the expected response even after following the steps above, try:

Adding a custom user agent to your Prerender allowlist
Selecting a user agent not blocked by your server or CDN
Using your SEO tool's actual crawler user agent in your test

More details: How to add additional bots

Method 2: Prerender App

The Prerender platform has a built-in domain verification tool accessible from two places. Both run the same check — use whichever you have open.

Option A — Get Started tab

Click Get started in the left sidebar.
Navigate to the Verify Integration step.
Enter your domain and click Verify Domain.

Option B — Domain Manager

Click Domain Manager in the left sidebar.
Add your domain and submit.

Common Issues and Solutions

Empty HTML Response

If you're getting only:

<html><head></head><body></body></html>

You may be using a framework (like Rails) that blocks I/O when rendering. Use a server that supports non-blocking behavior (e.g., Unicorn, Puma) to avoid render-time deadlocks.

JavaScript Still Showing

If you're seeing JavaScript in the returned page, your Prerender middleware might be running too late. Move the middleware config earlier in your route handling to ensure it runs before other logic.

Partial Page Rendering

Sometimes, your page may begin rendering before all assets load. You can use the window.prerenderReady flag to delay cache capture until content is ready:

Add this to your HTML:

<script>window.prerenderReady = false;</script>

Set it to true when your page is ready (for example after an AJAX call):

window.prerenderReady = true;

This ensures Prerender captures your page only after it has fully loaded.