lag

Then I suggest that you make an appointment at the Apple Genius Bar for service. If you need to find an Apple Store - Find a Store - Apple. Or you can call Apple Support directly.

Contacting Apple Customer and Support Service

1. Apple Store Customer Service at 1-800-676-2775 or visit online Help for more information.
2. Primary support help at Contact Support.
3. To contact product and tech support: Contacting Apple for support and service including international calling numbers.

Writing an effective Apple Support Communities question. If you have a question about an Apple product then please post it. If you are having problems with a non-Apple product then please use their tech support for help.

You posted very little information for any of us to try to help you with. We are not Apple employees here. Just other Apple-product users like yourself. Apple representatives, may or may not respond to posts.

All we know is that your experience with the Safari browser appears "laggy." Are you using the Safari app on an iPhone (running iOS 11.2.5) or another device? If another, what device and version of OS is it running?

Was this always an issue or just started happening recently? Does it happen whether your iPhone is connected to a wireless network or using a cellular data connection?

I suggest you use the program created by Etresoft, a frequent contributor. It will provide a snapshot of your system which we can analyze to possibly determine the cause of your problem. Please use copy and paste as screen shots can be hard to read. On the screen with Options, please open Options and check the bottom 2 boxes before running. Click “Share Report” button in the toolbar, select “Copy to Clipboard” and then paste into a reply. This will show what is running on your computer. No personal information is shown.

But you are shouting and rude. Why should we bother with you? You haven't even carefully read the replies already posted by me and Tesserax.