Offline link checker for built static sites

What it does

Checks a built folder such as dist/ or public/ directly, without running a server.

• Broken internal links (a tags pointing to pages that do not exist), with file and line number
• In-page links such as #section-id whose target id does not exist
• Missing images and files referenced by img, srcset, CSS url(), script, link, video posters, og:image and more
• Supports clean URLs (/about as /about.html or /about/index.html) and sub-path hosting (--base-path /docs)
• External links only with --external: one HEAD request at a time with a delay, retried with a small GET when HEAD is refused

How to use

python scripts/link_check.py dist --site-url https://www.example.com --md link-report.md
python scripts/link_check.py dist --external --delay 1.0

The agent reviews the results and proposes fixes in the source templates or content, not in the build output.

Requirements

• Python 3 (standard library only)
• Network access only when checking external links

Caveats

• Site files are never modified; only the report files you name are written.
• Links created by JavaScript at runtime and server-side redirect rules are not evaluated.
• HTTP 403/429 or TLS errors from external sites can be caused by bot protection or the local environment.