During the project setup, Ahrefs automatically detects organic competitors based on common:

Ahrefs identifies organic competitors primarily by analyzing common keywords that multiple websites rank for. If several sites consistently rank for a significant number of the same keywords as your project's domain, Ahrefs considers them organic competitors because they are vying for the same search engine visibility and audience. Referring domains and link profiles are crucial for backlink analysis and overall domain authority, but they are not the primary factor Ahrefs uses to automatically detect organic competitors during initial project setup. Organic competition is fundamentally about keyword overlap. IPs are irrelevant to competitor identification.