我建立了一个免费的专利搜索引擎，涵盖350万项美国专利——无需登录，基于SQLite FTS5

A patent lawyer who started coding in December 2025 has launched a free patent search engine covering 3.5 million US patents from 2016 to 2025. The search engine requires no login, has no ads, and no API keys, aiming to fill the gap in existing patent search tools. Current tools fall into two categories: simple Google Patents, which lack filtering and relevance tuning, and commercial tools like PatSnap and Derwent, which are powerful but cost over $10,000 per year. The new search engine offers fast full-text search across titles, abstracts, and claims, with CPC classification filtering and smart relevance ranking, providing users with a free middle-ground option.