Markdown link checker for a local folder

How the Markdown link checker reads the collection you selected

The checker resolves relative link and image destinations from each browser-reported source path. It decodes URI path characters conservatively, removes a query before file lookup and checks a fragment against a documented source-slug dialect. Full, collapsed and shortcut reference labels without a definition are all reported as undefined references. Exact paths win; a match that exists only after case folding or portable normalization is reported as ambiguous rather than guessed.

Raw HTML links inside Markdown are not inspected. The checker evaluates Markdown link syntax, but it does not parse <a href="…"> elements or treat a complete HTML document saved with a .md name as Markdown links.

How the deterministic source slug is formed

The CreatorValet source slug lowercases heading source text with the English locale, removes backticks and Markdown emphasis markers, keeps Unicode letters, numbers, underscores and hyphens, removes other characters, trims the ends and replaces each whitespace run with one hyphen. Duplicate headings add -1, -2 and so on in source order. This rule does not claim GitHub compatibility or reproduce another renderer's HTML anchors.

External Markdown links are inventory, not live status

HTTP, HTTPS, email and telephone targets are listed as external and never fetched. The tool does not claim that an external page is online, safe, current or correct. Root-relative links also remain unresolved because a browser folder picker cannot prove the future website root that will serve them.

Orphans, templates and front matter require an explicit rule

An orphan finding appears only after you name one or more entry files. Reachability then follows resolved local Markdown links from those entries. Structure comparison likewise needs one exact template path and compares ordered heading paths and levels without changing case or Unicode. Front matter field checks use only the dot paths and YAML 1.2 primitive types you enter; the collection is never treated as its own inferred schema.

The report is evidence, not a quality score

Copy findings puts every finding on the clipboard as a Markdown list, ready for an issue or a pull request comment, with external links grouped at the end. Download JSON report saves the full machine-readable record. The deterministic creatorvalet.markdown-collection-check/v2 report records browser-reported paths, origins, byte lengths, SHA-256 receipts, BOM and line-ending facts, each source's assessment and Markdown link-node count, selected rules and ordered findings with source spans. It contains no source text, timestamp, total score, freshness judgment or AI-readiness claim. Repeating the same bytes, paths, origins and options produces the same JSON bytes.

Your Markdown folder stays local

Directory selection, flat-file fallback, byte reading, UTF-8 decoding, hashing and checking happen in a browser worker as soon as you pick a folder, pick files or paste, and again whenever you change a selection or an advanced rule. Phones and tablets offer file selection only, because their browsers cannot pick a folder. Binary assets are inventoried without being decoded as Markdown, and one invalid UTF-8 Markdown file becomes a finding instead of erasing the report for every other file. There is no upload step and no arbitrary collection-size cutoff.

Use the Markdown diff to compare two source versions, the Markdown merger to combine documents, or the Markdown editor to change one document. This checker remains a read-only collection audit.