Unlike the Mac version of Safari, where updates for the browser are separate from the operating system, Apple updates the iPhone's Safari application through its standard iOS software updates. Your Safari application's current version is the same as the iOS 8 version your iPhone is currently using.
Check IOS Version
You can find your iOS 8 version information within the Settings application of your iPhone. After opening the Settings app, tap "General" followed by "About." In the About screen, scroll down to the Version tab to find your current iOS version. The iPhone lists the version information as three numbers, such as 8.0.2. The first is the overall version, which doesn't change unless there is a major update, while the remaining two numbers are internally used to denote minor revisions and bug fixes.
As Apple bundles important updates for Safari within iOS updates, making sure your iOS version is up-to-date ensures that your Safari application is as well. To update your iPhone, tap "Software Update," in the General screen. If an update is available, a number displays to the right of Software Update. To install an update, you must either have a 50 percent battery charge or connect the iPhone to a power source and Wi-Fi.