Ahrefs vs Open SEO Crawler

Ahrefs is a web and API platform for SEO research, including keyword research, rank tracking, site audits, backlink analysis and competitor research. It also provides content tools, AI assistants and MCP access. Content Explorer can find web mentions and link prospects, while AI Content Helper supports content improvement. The free plan provides site data and fixes with limited access to Site Explorer and Site Audit. Paid plans start with Starter at $29 a month. Lite costs $129 a month and includes five projects, 750 tracked keywords, 100,000 monthly crawl credits and one user; its Site Audit allowance has a 25,000-page project maximum. Annual payment saves up to 17%. Enterprise costs $1,499 a month and requires an annual commitment; it includes SSO, two-factor authentication, ISO27001 certification, access management, audit logs and unlimited additional users. Ahrefs says its web index contains 170 trillion pages, tracks 41.9 billion keywords and filters 28.7 billion keywords; AhrefsBot crawls 8 billion pages daily. Founded in 2010, the company is headquartered in Singapore. Multilingual support is available five days a week.

Open SEO Crawler is a free, self-hosted, open-source tool for auditing websites for technical SEO issues. It checks titles, meta descriptions, H1s, canonicals, structured data, redirects, HTTP errors, indexability, hreflang, mobile viewports, mixed content, images and security headers. It detects numerous CMS platforms, including Shopify, WordPress, Webflow, Wix, Squarespace, Kajabi, Ghost, Drupal, HubSpot and Joomla, then applies crawl recommendations. Optional Playwright rendering supports JavaScript-heavy sites, while compare mode identifies content absent from raw HTML.

Bulk reports can be exported to XLSX, and sitemap export is available. Default settings allow 1,500 pages, five workers, a 0.4-second per-host delay and depth 10; the page cap can be changed to unlimited. The crawler runs locally without accounts, telemetry or API calls, though it contacts target sites and checks GitHub for updates when requested. Installers are documented for Linux, macOS 11 or newer, and Windows 10/11. The project uses the MIT license.