librecrawl.com
LibreCrawl is a free, open-source SEO crawler offered as an alternative to Screaming Frog. It performs technical audits covering meta tags, schema markup, hreflang, social tags and PageSpeed metrics, and integrates Playwright for JavaScript rendering of single-page applications. The project is MIT-licensed and can be self-hosted, with CSV, JSON and XML exports. A REST API provides programmatic control of crawls.