Gutendex vs PoetryDB

Gutendex is a free, open-source JSON API — built independently of Project Gutenberg — that wraps its roughly 75,000 public-domain ebooks with searchable, paginated metadata: authors, subjects, bookshelves, languages, and direct links to every available download format from plain text to EPUB and Kindle. No account or key is needed to query it, and the project's own source enables cross-origin requests from any domain rather than restricting them. Anyone needing sustained high-volume traffic is asked to run their own instance of the open-source server instead of hammering the public one.

Keyless JSON API for a curated collection of roughly 3,000 English-language poems across 129 authors, queryable by author, title, line content, or poem-count/line-count filters, with matching results returned as full structured poem objects. Built and maintained as a free open-source project with no rate limits or usage tiers documented anywhere.