CrawlZilla vs Screaming Frog SEO Spider

CrawlZilla is a cloud-based SEO crawler for technical site analysis, available on the web and through an API. Its Spider, List and Subdomain modes can crawl HTML, images, JavaScript, CSS and PDFs. Each URL can include more than 40 data points, such as titles, canonicals, hreflang, schema and Open Graph information. An internal-link graph tracks links to help identify orphan pages and show PageRank flow; headless Chrome renders JavaScript pages. Lighthouse audits report Performance, Accessibility, Best Practices and SEO scores, plus Core Web Vitals. Page Monitor checks URLs on a chosen schedule, detects changes across 12 or more SEO fields and can send email alerts. Its REST API uses HTTPS, returns JSON and authenticates with bearer tokens. The free plan allows 10,000 URLs per session, 10 requests per second, three Lighthouse audits per crawl and 20 monitored URLs. Premium is £39.99 a month, with limits of 1,000,000 URLs per session, 20 requests per second, 10 Lighthouse audits per crawl and 500 monitored URLs. The maker says its distributed cloud infrastructure supports crawls of 100 million or more URLs and requires no installation or server management.

Screaming Frog SEO Spider crawls websites to audit more than 300 SEO issues and support improvements to search performance and user experience. It finds broken links and server errors, checks redirects, and flags page titles and meta descriptions that are missing, duplicated, or too long. For JavaScript-heavy sites, it can render pages with its integrated Chromium WRS, including sites using Angular, React, and Vue.js. Data extraction supports CSS Path, XPath, regular expressions, and custom JavaScript. The crawler connects to Google Analytics, Search Console, and PageSpeed Insights APIs, with link-metrics integrations for Majestic, Ahrefs, and Moz. Crawls can be scheduled, automated from the command line, exported to destinations such as Google Sheets, and compared across runs or between staging and production. The free version costs nothing and allows 500 URLs per crawl; saving crawls, configuration, and advanced features are restricted. The paid version costs $279 a year per licence, with unlimited crawl size subject to allocated memory and storage. It runs on Linux, macOS, and Windows.