Research depth
Discovery
How well the tool supports keyword, competitor, SERP, backlink, or market research before execution.
GrowthBar
Strong keyword, SERP, and competitor research coverage.
The official page says GrowthBar scans hundreds of Google SERP results and offers 7 billion keyword suggestions plus competitor keywords, Google Ads, and backlinks: https://www.growthbarseo.com/
Outranking
Strong SERP and competitor research depth.
The editor says it auto-collects research from ranking pages; the homepage says outlines read the top 20 ranking pages and expose competitor metrics. https://outranking.io/seo-content-editor/