Understanding Storage Quota | Workbox
जेफ पॉसनिक लिखते हैं, वर्कबॉक्स पर wrt A common source of unexpectedly high quota usage is due to runtime caching of opaque responses, which is to say, cross-origin responses to requests made without CORS enabled. Browsers automatically inflate the quota impact of those opaque responses as a security consideration. In Chrome, for instance, even an opaque response of a few kilobytes will end up contributing around 7 megabytes towards your quota usage.