[Wayback] How to view the html page source of a website in Safari – Macintosh How To
You can enable the extra menu in Safari by selecting ‘Preferences’ under Safari in the OS X menu bar and then under the ‘Advanced’ pane select the checkbox that says ‘Show Develop menu in menu bar.’
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This is the option you need:
a
MacOS – Safari – Show Develop menu in menu bar
–jeroen