Why Choose Our Online Markdown Local Link Validator?

Markdown Document Link CheckerDesigned for technical writers, documentation maintainers, and static site builders. It canrecursively scanall uploaded.mdfiles, automatically extract[text](path)format links, and verify each one to check iflocal files existand ifheading anchors (#anchor) match. External URLs (http/https/mailto) are intelligently skipped to avoid network interference and false positives. Under the hood, it uses the samecheck-doc-linksanchor slug algorithmas the Node.js version, accurately simulating GitHub Flavored Markdown's heading rendering rules to ensure detection results match the real rendering environment.

2026 Core Use Cases

Documentation Library Quality Assurance: Beyond CI/CD, provide teams with zero-cost local link pre-checks to prevent 404 broken links after documentation goes live.
Open Source Project Contribution Collaboration: Maintainers can quickly verify if documentation links in PRs point to correct local files or anchors, improving review efficiency.
Knowledge Base / Wiki Maintenance: Individuals or teams can batch-check if internal cross-references are broken when migrating or restructuring documentation.
Static Site Generation Preprocessing: Before building a blog or technical site, ensure all cross-references between Markdown source files are complete and correct.

Frequently Asked Questions (FAQ)

Q: Will the tool read sensitive files on my computer?

Absolutely not. All files are processed only in browser memory and are never uploaded to any server. Uploaded files are used solely for local link parsing and anchor matching; data is automatically cleared when the page is closed.

Q: Can links containing paths (e.g../docs/guide.md) be matched correctly?

Yes. The tool extracts the filename from the path for matching; if the browser supportswebkitRelativePath(Chrome/Edge, etc.), after uploading a folder, the tool uses the full relative path for precise matching, achieving higher accuracy.

Q: What are the matching rules for anchors (#section)?

The tool uses a GitHub-consistent slugification algorithm: removes HTML tags and special characters, converts to lowercase, and replaces spaces with hyphens. For example,## My Feature (v2.0)is converted to#my-feature-v20. Anchors in links are processed the same way before comparison.

Q: How many files can be checked at once?

No limit. However, it is recommended to upload no more than 200 files at a time to avoid browser rendering lag. The tool checks every local link in each file and provides a summary.

3 Key Advantages Over Similar Tools

Fully Browser-Based, Zero Installation, Zero Dependencies: No need to install Node.js, Python, or any command-line tools. Open the webpage and use it immediately, ideal for non-technical writers and quick validation scenarios.
Anchor Accuracy Aligned with GitHub's Rendering Engine: The slug algorithm covers most special characters and nested tag scenarios in GFM, with a much lower false positive rate than simple regex-based solutions.
Interactive Visual Report: Results are displayed in three color-coded categories: "Valid / Invalid / External Skipped," along with source file paths and specific error reasons, making it more intuitive and readable than plain CLI logs.

Long-Tail Keywords: Markdown local link detection · Document anchor validation tool · Static site broken link check · Open source project documentation quality · Browser-based md link analysis · GFM anchor slug matching · Multi-file document validation.