Call response.fromServiceWorker() on the HTTPResponse object. It returns true if a service worker served that response and false otherwise. In a page response listener, the response event provides the object to check.
Check the response in a page event
Register a listener for the page’s response event and inspect each response with fromServiceWorker():
page.on('response', response => {
if (response.fromServiceWorker()) {
console.log('Served by a service worker:', response.url());
}
});The event supplies a Puppeteer HTTPResponse. The method is documented in the Puppeteer API; the cited reference displays version 25.4.0. If you need to verify availability or signature for a different installed version, check that version’s API documentation: HTTPResponse.fromServiceWorker().
Understand what the result tells you
fromServiceWorker() answers a provenance question: did a service worker serve this response? It is distinct from whether the browser used its memory or disk cache. Puppeteer documents the two methods separately in the HTTPResponse API.
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- Use
response.fromServiceWorker()to check service-worker provenance. - Use
response.fromCache()to check whether the response came from browser cache. - Do not treat a cache result as proof that a service worker was or was not involved.
Do not confuse a response with an interception decision
When request interception is enabled, Puppeteer stalls requests until your code continues, fulfills, or aborts them. Methods such as isInterceptResolutionHandled() and interceptResolutionState() describe how interception has been resolved; they do not identify the source of the resulting response. Use HTTPResponse.fromServiceWorker() for that check. See the Puppeteer network interception guide.
Responses with HTTP error status codes
A response event can still occur for an HTTP error such as 404 or 503. An unsuccessful status code alone does not make it a request failure event. You can inspect the service-worker flag and the response status separately. The Puppeteer page events documentation describes the response event and this distinction.
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