The Data Accumulation Vector
As you browse the web on your iPhone, Safari continuously downloads and hoards website assets—images, tracking cookies, and layout files—to accelerate future loading times. Over several months, this local cache can consume gigabytes of precious internal storage. Furthermore, if a website developer updates their server, but Safari stubbornly loads an outdated layout file from your local cache, the webpage will appear visually broken or refuse to accept your login credentials. You must routinely purge this database.
How to Clear the Cache in Safari
Apple does not allow you to clear the cache directly from within the Safari browser interface itself; you must execute a system-level wipe through the primary iOS Settings application.
1. Close Safari entirely and open the main Settings app on your iPhone.
2. Scroll down the main list of applications until you locate Safari (it features a blue compass icon). Tap it.
3. Scroll down the Safari configuration page. You are looking for a specific option written in prominent blue text.
4. Tap the option labelled Clear History and Website Data.
5. A dialogue box will slide up from the bottom of the screen.
6. Select the Timeframe: iOS now allows you to choose how much data to destroy. Select All history to perform a complete, absolute wipe of the cache.
7. Tap the red Clear History button at the bottom of the screen.
Crucial Consequence: The operating system will instantly obliterate the cache and delete all tracking cookies. This means you will be forcibly logged out of every single website you were previously signed into (Amazon, Twitter, webmail, etc.), and you will need to re-enter your passwords the next time you visit those domains.