1. Plug your iPhone or iPad to your Mac.
2. Go to Settings -> Safari -> Advanced -> enable Web Inspector
3. Browse to any website on your iPhone or iPad in Safari. Keep the page open on your device.
4. Open Safari on your Mac. While your iPhone or iPad is still plugged into your computer, go to Develop menu and find your device then choose the website page you want to debug.
5. Now, you can your iPhone or iPad Safari web page in full developer mode with debug information including elements, network, resources, timelines, debuggers, storage, and console parameters.
6. You can even control refreshing the web page on your device from your Mac!