With the (somewhat) recent release of iOS 6 comes the built-in ability to debug your iOS browser using Safari on your mac. Now there are other ways to do this, but the beauty of this method is that if you have a mac running Lion, and an iPhone/iPad running iOS6 – everything you need is already there, no extensions/apps required.
Step 2. On your mac, go to Safari preferences, click the Advanced tab, and check “Show Develop menu in menu bar.”
Step 3. Connect your device to the mac using a USB cord, then visit a site in your device’s browser.
Step 4. On the mac open up Safari, and click the Develop tab – your device should appear in the dropdown menu. Select the site you’d like to inspect and the web inspector should appear.