CharityBase is a free, open source database and GraphQL API that aggregates fragmented data from the Charity Commission, Companies House, 360 Giving, charity websites, the ONS, and social media into a single, cleaned, normalized, and searchable dataset. It powers a public search portal where users can discover detailed profiles of UK charities, complete with finance, governance, and activity data, and offers a single GraphQL endpoint that responds in structured JSON with custom queries for counts, aggregates, and detailed lists. Designed to eliminate the heavy lifting of data collection and cleaning, CharityBase enables startups, grantmakers, and researchers to build digital tools, such as dashboards, reports, and grant-finding applications, without managing their own data pipeline. Its API supports both GET and POST requests, variable-driven queries, pagination, and live interactive playgrounds for rapid prototyping, all underpinned by regularly updated, audit-trail-backed records.