1.Tap Safari (iPhone or iPad), if it is not already open, and visit this page.
2.Tap the Action button:
4.Tap the Name Field and hit the X icon to clear it and name it “Show Page Source” and then tap “Save”.
6.Tap the Bookmarks icon and tap Edit:
7.Tap the “Show Page Source” bookmark you just created in step # 4:
Done! Now you can to to any web page using mobile Safari on your iOS device (iPhone or iPad), tap the Bookmarks icon then tap the Show Page Source bookmark and a new window will open displaying the source code of the webpage.