WhoisXML API - Domain, IP, and DNS data provider
Oribi - Analytics for marketing & product teams
Abstract APIs - Simple, powerful APIs for everyday dev tasks
Antideo - Email, IP address and phone number validation API service
BrandHunt V2 - Search/track domain & social media handles in real time.
Ahrefs - Ahrefs is a toolset for SEO and marketing. We have tools for backlink research, organic traffic research, keyword research, content marketing & more. Give Ahrefs a try!