Google Dataset Search
datasetsearch.research.google.com
A search engine specifically for finding datasets hosted across the web, using structured metadata to surface publicly available research data.
Why it is useful
Solves the hardest part of data science work — finding the right dataset in the first place — by crawling repositories, government data portals, and academic data stores. Many datasets it surfaces are invisible to normal web search because they are buried in domain-specific repositories. The metadata filtering by file format, update frequency, and license type is practically very useful.