As an SEO you may be taking the full advantage of FireFox’s built-in “View source” option. I used it multiple times for any type of webpage You can create it so easy. A few ways to make viewing the source code of any page more usable.
X-Ray is a great FireFox addon that makes it much easier to compare the source code with an actual website interface design. In fact, it inserts coding right within the page, so you can clearly see which code is used for which web page element.
When applied to a page it can help you see how the document was constructed without having to go back and forth between the source code and the page in your browser.
This way the addon, makes it much easier to:
* See the page HTML Website (semantic) structure including the headings
* See the document structure including and classes, etc.