allstrategy usesversionpassed tooptionsas a cache tag. When version changes, old version cache is removed and new files are downloaded. Of course if files with the same name were not changed (HTTP status 304), the browser probably won't download them again and will just update cache.changedstrategy is more advanced thanall.offline-pluginwill calculate the files' hashes on it's own, independent ofwebpacks hash calculation. Even if a file is renamed, if the hash is the same, it will not be downloaded again, but rather just renamed. With this strategy enabled,index.html(or other files without dynamic name) should be placed inmainsection of the cache, otherwise they won't be revalidated.- For
ServiceWorkerthis means that only new/changed files will be downloaded and missing files deleted from the cache. AppCachedoes not support thechangedstrategy and will always use theallstrategy.
- For
updateStrategydoes not apply toexternals, as they're always revalidated/redownloaded onServiceWorkerupdate.