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.
Yoast SEO
Useful keyword and site-content insights, but not a full standalone SEO research suite.
Yoast says Premium analyzes up to five keyphrases and its free plugin integrates Semrush for expanded keyword research: https://yoast.com/wordpress/plugins/seo/ and https://yoast.com/product/yoast-seo-wordpress/