What should I do if I am experiencing high volumes of unwanted renders?

TL;DR

Unwanted renders happen when unnecessary URLs are sent to Prerender.io for rendering. Common causes include duplicate query parameters, soft 404 pages, static file extensions, and internal URLs being forwarded to Prerender.io. Fix them by using the Ignore URL feature, correcting your server's 404 responses, and configuring your integration to exclude non-HTML resources.

Why this matters

Prerender.io renders a page every time a bot requests a URL that is forwarded through your integration. Each render counts toward your plan's usage. If unnecessary URLs are being forwarded, you pay for renders that provide no AI & Search visibility benefit.

Prerender.io does not decide which URLs to render. Your integration controls which bot requests are forwarded to Prerender.io. If unwanted URLs are being rendered, the fix is almost always in your integration configuration or your server's response codes.

Common causes of unwanted renders

Before applying fixes, identify which of these scenarios applies to your site:

• Query parameters that do not change page content. URLs like yoursite.com/page?tracking=abc and yoursite.com/page?tracking=xyz produce identical content but count as separate renders.
• Soft 404 pages. Your server returns a 200 status code for pages that do not exist, so Prerender.io renders them instead of skipping them.
• Static file extensions. Requests for .js, .css, .png, .jpg, .svg, .pdf, .woff, and similar files are being forwarded to Prerender.io instead of being excluded.
• Internal or private URLs. Admin panels, staging pages, or API endpoints are being forwarded to Prerender.io.
• Bot requests for error pages. Bots request broken or outdated URLs, and your server returns 200 instead of the correct error code.

Step 1: check your render logs for patterns.

Log in to your Prerender.io dashboard and review your recently rendered URLs. Look for:

• URLs with query parameters that appear repeatedly with different values.
• URLs that return error content but were rendered as 200.
• Static file URLs (.js, .css, .png, etc.) that should not be rendered.
• Internal URLs that should not be visible to crawlers.

Step 2: use the Ignore URL feature to filter unwanted URLs.

Prerender.io's Ignore URL feature prevents specific URL patterns or query parameters from being rendered.

1. Log in to your Prerender.io dashboard.
2. Navigate to Cache Manager, then Caching Rules.
3. Add the URL patterns or query parameters you want to exclude.

How each filter type works:

• Ignored URL patterns. Prerender.io returns a 404 for matching URLs and does not count them against your render limit. This prevents rendering of pages that should not be indexed.
• Ignored query parameters. Prerender.io strips the ignored parameter and serves the cached version of the base URL to bots instead. For example, yoursite.com/page?tracking=abc is served as yoursite.com/page. These requests are also not counted against your render limit.

See Ignore URLs and query parameters for detailed configuration instructions.

Step 3: fix soft 404 pages.

If your server returns a 200 status code for pages that do not exist, Prerender.io renders them as normal pages. Fix your server to return proper 404 status codes for missing content.

1. Use the Prerender.io 404 checker to identify soft 404 pages on your site.
2. Follow the steps in why is Prerender.io caching my 404 pages as 200? to fix the issue.

Step 4: exclude static file extensions from your integration.

Configure your integration to skip non-HTML file extensions. Files like .js, .css, .xml, .png, .jpg, .jpeg, .gif, .svg, .pdf, .woff, and .ttf should never be forwarded to Prerender.io.

The official Node.js middleware excludes a wide range of static file extensions by default. Other integrations, particularly server-level configurations (Nginx, Apache, IIS), typically require manual exclusion rules. Check your integration's documentation to verify whether static extensions are excluded, and add exclusion rules if they are not.

Step 5: modify your integration to exclude internal URLs.

If admin panels, staging pages, or API endpoints are being forwarded to Prerender.io, update your integration to exclude them. The exact implementation depends on your integration method, but most integrations support URL pattern exclusions.

Step 6: verify your changes.

After applying your fixes, monitor your render logs for several days to confirm the unwanted renders have stopped.

1. Check your Prerender.io dashboard for a reduction in total renders.
2. Review the rendered URL list to confirm the filtered URLs no longer appear.

Related articles

• How to reduce the number of cached pages in Prerender.io
• Why is Prerender.io caching my 404 pages as 200?
• Ignore URLs and query parameters