Arachnide and Screaming Frog SEO Spider
Arachnide was built by a Screaming Frog user, for the same job: a desktop crawl that becomes a technical audit. This page lists what the two tools share, where Arachnide goes further and what it does not do. It is not a ranking.
Arachnide is an independent project, not affiliated with Screaming Frog Ltd. “Screaming Frog” and “SEO Spider” are trademarks of their owner. Facts about Screaming Frog come from its public website; check them there before deciding, they change with each release. screamingfrog.co.uk
| Criterion | Arachnide SEO Spider | Screaming Frog SEO Spider |
|---|---|---|
| Price and licence | Free, open source (MIT). No page limit tied to a licence; the default budget of 500 pages is a setting. | Free version limited to 500 URLs; paid annual licence for unlimited crawling and advanced features. |
| Where it runs | On your computer (macOS, Windows, Linux), Node.js 18.17+, web interface on 127.0.0.1. | On your computer (Windows, macOS, Ubuntu), Java desktop application. |
| JavaScript rendering | Yes, with the Chrome or Edge already installed. | Yes, with a bundled Chromium. |
| Checks and audit | About 95 checks with explanation and fix, health score, pillars, action plan. | Extensive crawl data and issues reports; see its documentation. |
| Fixes applied to the site | Yes: AI proposals, human approval, connectors for WordPress, Shopify, Webflow, Wix, Joomla, Drupal, PrestaShop, files, Cloudflare Worker, GitHub PR; history and undo. | No write connectors; exports for the team to apply. |
| AI agents | 25 tools over MCP and REST + OpenAPI 3.1, GEO readiness score. | AI features in recent versions (check the current list on its site). |
| Segments | Yes (3.14), rules on 20 fields, first match wins. | Yes. |
| Site visualisations | Classic crawl tree, directory tree, link graph, 2D and 3D. | Crawl tree, directory tree, force-directed diagrams. |
| Google data | PageSpeed Insights / CrUX, Search Console (API or CSV), Google Analytics 4 (API or CSV). | PageSpeed Insights, Search Console, Google Analytics integrations. |
| Scheduling and alerts | Scheduled crawls with e-mail alerts and comparison with the previous crawl. | Scheduling in the paid version. |
| Reports | White-label PDF report in 6 languages, comparison between two crawls. | Exports, crawl comparison, Looker Studio / Data Studio reports. |
| Interface languages | 6: English, French, Spanish, Italian, Portuguese, German. | See its site. |
| Source code | Public on GitHub, MIT, pull requests welcome. | Proprietary. |
What Arachnide does not do (today)
- Log file analysis: Screaming Frog sells a separate Log File Analyser; Arachnide has nothing equivalent.
- Spelling and grammar checks.
- Forms-based authentication (logging in through a web form). Arachnide supports HTTP authentication and custom headers or cookies.
- A vendor, a support team and fifteen years of track record. Arachnide is one developer and a GitHub issue tracker.
- Crawl data views that only a mature product accumulates. If a column you rely on is missing, open an issue.
Where Arachnide goes further
Everything after the crawl: Claude or ChatGPT write the missing titles, descriptions and alt texts from the real page, you approve them, and the change lands in your CMS through a connector, is re-crawled and can be undone. The same engine is exposed to AI agents through MCP and REST, so your own agent can audit and fix a site end to end.