Soft 404 Audit Claude Skill
This skill audits a website for soft 404s and produces an actionable report. A soft 404 is a page that returns 200 OK but is really a not-found or empty page — it wastes crawl budget and can get real URLs dropped from the index. The skill crawls pages and sends a missing-page probe to find error pages served with a 200 status, a server that returns 200 for every unknown URL instead of a real 404 or 410, thin pages matching the site's error template, and empty or near-empty pages.
Quick Take
Point the skill at a site root or a URL list of the pages Search Console flagged. It probes a deliberately missing URL to learn the site's error template, then compares live pages against it and returns a prioritized report of soft 404s.
What The Skill Checks
- Error template detection: a missing-page probe that reveals whether the server returns a real 404/410 or a 200 for every unknown URL.
- Disguised errors: error pages served with a 200 status and thin pages matching the site's error template.
- Empty pages: empty or near-empty 200 pages below the thin-word threshold, raised for content-heavy sites.
How The Skill Is Packaged
The skill follows the standard Claude Agent Skill structure: a SKILL.md file with YAML frontmatter and workflow instructions, a references/ folder with the full audit check definitions and report template, and a scripts/ folder with Python scripts that crawl the site and send a missing-page probe to extract the error template, then audit each live page against it. Install it with npx claude-seo-skills install soft-404-audit, or copy the skill folder into your Claude skills directory; Claude invokes it automatically when a request matches its description.
Skill Files
Every file in the skill is embedded below directly from the Claude-SEO-Skills repository, so you can review exactly what the skill instructs Claude to do before installing it.
SKILL.md
The skill definition: frontmatter, inputs to collect, the workflow, and the resources the skill relies on.
Audit Checks Reference (references/audit-checks.md)
Full definitions, severities, and rationale for every check across the high, medium, and low tiers.
Report Template (references/report-template.md)
The output structure the skill follows, including the sections issues are grouped into.
Page Extractor Script (scripts/extract_pages.py)
Crawls pages and sends a missing-page probe to capture the site's 404/error template and each live page's content signals.
Soft 404 Auditor Script (scripts/audit_soft404.py)
Compares each live page against the error template and thin-content threshold, then outputs the structured report data.