Know what happens when rendering does not complete.
Managed DNS and developer integrations do not fail in exactly the same way. This page documents the current behavior so a team can choose its own retry, fallback, and rollback expectations before cutover.
Prerender Buddy does not claim universal fail-open behavior or zero-downtime rendering.
Implementation reviewed: July 13, 2026.
Visitors keep the origin path
Managed DNS sends normal visitors, unmatched agents, and excluded routes to the configured origin.
Stale cache can protect quota exhaustion
When a stale rendered entry exists, it can be returned after the fresh-render quota is reached.
Middleware controls its fallback
A developer integration receives status codes and must define how its platform handles a non-success response.
Managed DNS path
Proxy behavior for the connected domain.
These outcomes apply to the current managed proxy. The configured origin must remain public and separate from the proxied hostname.
Normal visitor or unmatched crawler
The request goes to the configured origin.
API, asset, private route, or non-GET request
The crawler render path is bypassed and the request goes to the origin.
Site is outside the plan site limit
The origin response is returned with an X-Prerender-Site-Limit header.
Fresh-render quota reached; stale cache exists
The stale rendered HTML is returned with a quota header.
Fresh-render quota reached; no stale cache
The request falls back to the origin response.
Render engine returns an HTTP error
The engine status and response are forwarded to the crawler.
Engine or origin request times out or throws
The proxy returns an error response; it does not guarantee an origin fallback.
Origin missing or loops to the public hostname
The proxy returns a configuration error instead of repeating the request loop.
Developer API path
The integration owns the final response policy.
The maintained Netlify edge example converts non-success render API results to 503. Other middleware must be reviewed on its own behavior.
Missing or invalid API key
The render API returns 401.
URL is not registered to the API key workspace
The render API returns 403.
Site is outside the plan site limit
The render API returns 402.
Fresh-render quota reached; stale cache exists
The stale rendered HTML and its original document status are returned.
Fresh-render quota reached; no stale cache
The render API returns 429.
Render capacity reached
The rendering engine returns 503 with a short Retry-After value.
Render fails or times out
An error response is returned. The customer middleware decides whether to pass it through, retry, or use an origin fallback.
Origin page returns a document status below 500
That status is preserved and may be cached. Engine-side 5xx documents are not cached.
Setup failures
DNS and HTTPS complete before crawler traffic is ready.
DNS pending
Confirm records at the provider serving the domain's authoritative nameservers. DNS propagation and provider polling can delay the displayed state.
HTTPS pending
Use the current validation records shown in the dashboard. Values from a previous reset can no longer complete the current certificate request.
Origin error
Verify that the origin URL is public, serves the intended site, does not redirect to the proxied hostname, and can be reached without authentication.
Protected page
Remove authenticated or sensitive pages from crawler rendering. A login wall or blocked resource should not be worked around by placing credentials in the URL.
Before changing production traffic
Test representative routes and keep a rollback path.
Check success, redirects, 404 pages, slow pages, private routes, and an intentional render failure. Monitor crawler logs after cutover.