Research depth
Discovery
How well the tool supports keyword, competitor, SERP, backlink, or market research before execution.
AlsoAsked
Strong depth for People Also Ask and intent-map research, but narrower than a full SEO suite with backlinks, crawling, and rank data.
The homepage describes live People Also Ask data, intent clustering by Google, country, city, language, search-depth controls, Deep Search, bulk searches, and a case study using the data for long-tail keyword growth.
SpyFu
Broad historical competitor SEO/PPC dataset and many research views.
The homepage says users can see competitors' SEO/PPC keywords and every ad they have tested; https://www.spyfu.com/