The PWA that served Googlebot a six-month-old homepage

The PWA that served Googlebot a six-month-old homepage

A marketplace went full PWA. Months later, their homepage kept ranking for products that no longer existed, and new collections never surfaced. The live site was current; the indexed version was a fossil.

We checked the rendered HTML Google stored: an old layout, retired categories, dead promotions. But the live URL served fresh content. Where was the stale version coming from?

Their service worker used a cache-first strategy for the app shell and key HTML routes. Googlebot's renderer registers and runs service workers. On recrawl, the service worker intercepted the request and served the cached, months-old HTML from its own cache before the network ever responded.

Google was effectively rendering against the site's own offline cache, frozen at whenever the service worker last cached it.

A cache-first service worker can pin Googlebot to a stale snapshot it serves to itself — invisible unless you realize the crawler runs your service worker.

Fix: network-first strategy for HTML documents, cache-first reserved for static assets only.

Result: indexed content caught up to live within two weeks, stale-product rankings cleared, and new collections began indexing same-week — organic sessions +22% once the fossil cleared.