Research depth
Discovery
How well the tool supports keyword, competitor, SERP, backlink, or market research before execution.
Google Trends
Useful directional topic and query-interest research, without SEO difficulty, backlink, crawl, or SERP-depth data.
Explore and Trending Now show public search-interest patterns over time. https://trends.google.com/trends/
Majestic
Deep backlink research across URL, domain, referring-domain, anchor-text, topic, link-context, competitive, fresh, and historic views.
Site Explorer documents domain/hostname/URL analysis, Trust Flow, Topical Trust Flow, anchor text, new/lost links, Link Graph, Similar Sites, and 15+ years of Historic data: https://majestic.com/reports/site-explorer