CrawlZilla vs SEO4Ajax

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.

SEO4Ajax uses dynamic rendering to make AJAX content visible to search engines and social networks. It can be configured on Apache, nginx, PHP, Java EE, Ruby, Python and Node.js servers, and supports frameworks including React, Vue.js, Angular, AngularJS, GWT, Ember and Backbone. The service says it can handle thousands or millions of pages without website code changes. Its REST API supports customization and automation, while a dashboard tracks bot activity, cache freshness, duplicates and broken links. SEO4Ajax caches snapshots, can capture inner links, and supports custom recache periods and email alerts for quota overages, scraping errors or unreachable websites. SEO reports flag indexing issues such as broken links, duplicates and invalid hreflang tags. The Developer plan is free, with 1,000 pages and 2,500 snapshots per month. Paid plans start at $29/mo (annual), and include email support at listed response times. The service is for business use, not personal, family or household use.