Move without breaking the links people already use
A new website does not mean starting from zero. Other sites may already link to your old pages, people may have bookmarked them, and search engines may know and rank those URLs. During a migration, the goal is to make sure anyone opening an old address reaches the right new page, while preserving as much of the SEO value you've already built up as possible.
The process below takes you from the initial audit through to the checks after launch. You can do every step manually, but you do not have to click through everything one item at a time.