What is the difference between technical SEO and on-page SEO?

Technical SEO covers infrastructure that usually applies across an entire site at once: crawlability, page speed, mobile usability, and indexing. On-page SEO instead covers the content and structure of just one specific page at a time.

A useful way to separate the two: technical SEO decides whether a page can be found and read properly at all in the first place. On-page SEO decides whether that page, once found, is actually any good.

Both matter together in practice. A perfectly written page sitting on a slow, poorly indexed site still struggles to rank, and a technically flawless site full of thin pages does not rank well either.

Both boxes get checked automatically before anything from automatic SEO software goes live.