Find [text][ref] links where the [ref]: definition is missing, and unused definitions that bloat the doc.
Paste Markdown with [text][ref] links to scan for broken references.
Free Markdown Broken Reference Detector scans your document for reference-style link problems: [text][label] references missing their [label]: URL definition, definitions that no reference points to, and empty labels. It catches the silent failures that render as plain text instead of clickable links.
Privacy: This tool runs entirely in your browser. Your text is never uploaded, logged, or cached. Close the tab and it's gone. Verify in DevTools → Network: zero requests fire.
Broken reference links silently fail in Markdown renderers. Finding them should not require a linter setup. The detector runs 100% client-side.
| Input | Output | Typical size | Speed | Login needed |
|---|---|---|---|---|
| Markdown (.md) | Issue report | Any document size | < 10 ms | No |
Here's what this free tool does in detail — every feature is built to solve real problems, runs entirely in your browser, and is free forever.
Every [text][label] reference is checked against all [label]: URL definitions in the document. Missing definitions are flagged as errors because the link will render as plain text, not a clickable link.
For inline link checking, use the Broken Link Finder.
Definitions that no reference points to are flagged as warnings. They bloat your document and can confuse editors who expect every definition to be used somewhere.
References with empty labels like [text][] are flagged as errors. While some renderers treat them as shorthand, they are unreliable across platforms and should be made explicit.
References and definitions inside fenced code blocks are ignored. Only references in actual content are analyzed, so code examples do not produce false positives.
For overall document structure validation, try the Structure Validator.
Paste a document that uses [text][label] reference-style links.
Missing definitions, unused definitions, and empty labels are listed with line numbers.
Click Copy report for a plaintext summary to guide your fixes.
Catch broken reference links before they ship as plain text.
Keep definitions in sync with references across large documents.
Verify that contributed docs have valid reference links.
Find and remove unused definitions that bloat the document.
Ensure reference-style links survived the migration intact.
Yes. Free forever, no account required.
Links written as [text][label] with a separate [label]: URL definition line. They keep prose clean by separating URLs from text.
No. It only checks [text][label] references. For [text](url) links, use the Broken Link Finder.
Most renderers display [text][label] as plain text instead of a link. The reader sees brackets, not a clickable link.
No. Runs 100% in your browser.