CrawlZilla vs Screaming Frog SEO Log File Analyser

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 Log File Analyser is a desktop application for examining access logs and understanding search engine and AI bot activity. It installs locally and keeps log event data in a local database. It accepts Apache, W3C Extended, and Amazon Elastic Load Balancing logs, and can verify supported bots to identify spoofed requests. Reports cover crawled URLs, crawl frequency, response errors, redirects, bytes downloaded, and response times. Users can match imported data containing a URLs column against log activity, including crawls, directives, or external link data. Log files can be added by drag and drop, with analysis exported to CSV or Excel. The software can process millions of events, though capacity depends on hard drive space. It runs on Linux, macOS, and Windows. The free plan allows 1,000 log event lines and one project. The paid licence costs $139 per year and includes unlimited events and projects, subject to storage capacity. Free technical support is listed for both versions.