CrawlObserver vs Screaming Frog SEO Log File Analyser

CrawlObserver is a free private-beta SEO crawler available through web and API access. It reports more than 45 signals per page and describes audits without a page ceiling, including sites with 500K+ pages. Crawl comparisons identify added or removed URLs and changes to redirects, titles, and canonicals. Technical checks include redirect chains, internal PageRank, SimHash duplicate detection, and broken internal or external links. Internal authority-flow views help surface orphan pages, linking opportunities, and pages receiving too many links. JavaScript rendering can be off, automatic, or always enabled, with automatic detection for React, Vue, Next.js, and Nuxt. A REST API launches crawls and retrieves results. CrawlObserver says it follows robots.txt and crawl-delay, applies per-host delays, and blocks private IP ranges with post-DNS validation. Results are stored in ClickHouse.

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.