If you want to maintain your Google rankings when redesigning your page you should maintain the following as much as possible:
- Page title (
- The main content text that is used on the page
- The link structure (which pages link to it and which ones it links to)
- The URL
I have done many page redesigns that change the layout, colors, styles, and images without hurting SEO rankings. It is even possible to make some changes to the items that I listed without hurting your rankings, but the more changes that you make, the riskier it becomes.
Unfortunately, if your Google rankings do fall, it has been my experience that reverting does not cause your rankings to come back quickly. Google seems to remember coding mistakes and ill thought out changes. Rankings may suffer, even after correcting the problems.
Google may do this for a couple reasons:
- Your reputation suffers in their eyes when your site changes for the worse. Changing it back doesn't help your reputation much because you now have a reputation for screwing up.
- Positive changes may take a while to increase rankings. Google may do to make SEO experiments harder to conduct. They don't like webmasters to know which changes make them rank better. Delaying good rankings after changes are made make clarity on which changes matter harder to infer.