24 | | ''Safari for iPhone will only cache files 25 KB or smaller served using the Expires explicit expiration time or Cache-Control max-age directive HTTP headers. Safari decodes the file before saving it cache, meaning your total unzipped file size must squeeze under the 25 KB ceiling to hit the cache. Components already in cache are only replaced by new cacheable components using the least recently used algorithm. Safari for iPhone is able to cache a maximum of 19 external components, placing a maximum cache limit at around 475 KB.'' |
| 23 | ''Use far-future cache expiration headers. This will prevent the browser from having to send a conditional GET request. |
| 24 | Try to limit HTML pages to 25.6KB or less if you want them to be cached, since the previous tests showed that this limit—imposed by iOS 3.2 on the iPad—was the lowest HTML resource limit of the devices tested. |
| 25 | Keep CSS and JS components under 1MB. Of course, 1MB is enormous and your components should be much smaller than this, but don’t bother splitting a component into separate requests for the sake of cacheability unless its size approaches 1MB. |
| 26 | Consider using the HTML5 application cache if it’s important that your components persist in the cache for a long time, or across power cycles.'' |