Clearing UIWebView's Cache in Swift

You can use

NSURLCache.sharedURLCache().removeAllCachedResponses()
NSURLCache.sharedURLCache().diskCapacity = 0
NSURLCache.sharedURLCache().memoryCapacity = 0

Swift 3.0

URLCache.shared.removeAllCachedResponses()
URLCache.shared.diskCapacity = 0
URLCache.shared.memoryCapacity = 0

You can also change the cache policy of the NSURLRequest

let day_url = NSURL(string: "http://www.domain.com")
let day_url_request = NSURLRequest(URL: day_url,
    cachePolicy: NSURLRequestCachePolicy.ReloadIgnoringLocalAndRemoteCacheData,
    timeoutInterval: 10.0)

let day_webView = UIWebView()
day_webView.loadRequest(day_url_request)

Swift 3.0

let day_url = URL(string: "http://www.domain.com")
let day_url_request = URLRequest(url: day_url!,
    cachePolicy:NSURLRequest.CachePolicy.reloadIgnoringLocalAndRemoteCacheData,
    timeoutInterval: 10.0)

let day_webView = UIWebView()
day_webView.loadRequest(day_url_request)

For more information on cache policies : https://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/NSURLRequest_Class/index.html#//apple_ref/c/tdef/NSURLRequestCachePolicy

Swift 4:

final class WebCacheCleaner {

    class func clear() {
        URLCache.shared.removeAllCachedResponses()

        HTTPCookieStorage.shared.removeCookies(since: Date.distantPast)
        print("[WebCacheCleaner] All cookies deleted")

        WKWebsiteDataStore.default().fetchDataRecords(ofTypes: WKWebsiteDataStore.allWebsiteDataTypes()) { records in
            records.forEach { record in
                WKWebsiteDataStore.default().removeData(ofTypes: record.dataTypes, for: [record], completionHandler: {})
                print("[WebCacheCleaner] Record \(record) deleted")
            }
        }
    }

}

// Usage
WebCacheCleaner.clear()

---

Older Versions:

NSURLCache.sharedURLCache().removeAllCachedResponses()
if let cookies = NSHTTPCookieStorage.sharedHTTPCookieStorage().cookies {
    for cookie in cookies {
        NSHTTPCookieStorage.sharedHTTPCookieStorage().deleteCookie(cookie)
    }
}

Swift 3.

URLCache.shared.removeAllCachedResponses()
URLCache.shared.diskCapacity = 0
URLCache.shared.memoryCapacity = 0

if let cookies = HTTPCookieStorage.shared.cookies { 
    for cookie in cookies {
        HTTPCookieStorage.shared.deleteCookie(cookie)
    }
}