Serper (Google Search API)

2,500 free search queries just for signing up

Covers web, image, news, maps, places, video, shopping, scholar, patent, autocomplete, and other search types. No credit card required. The official page doesn't state whether this quota resets monthly — it's generally understood to be a one-time grant.

⚠️Markets itself as 'the fastest, cheapest Google Search API'; the one-time 2,500-query quota is suited to prototyping — heavy use requires switching to paid.