Markdown Checker — Find Broken Links, Headings, and Code Fences

Category: Text · URL: /tools/markdown-checker.html

Markdown input

Check heading level jumps Check heading space after # Check empty/unclosed link URLs Check trailing whitespace Check tab characters

Tip: For reformatting, try Markdown Formatter or the VS Code-friendly formatter.

Report

Privacy: runs locally in your browser. No uploads, no tracking scripts.

How to use

Run checks locally in your browser (no uploads).

Paste Markdown into the input box.
Pick which checks you want to run.
Click Check Markdown.
Fix items in the report (use the line numbers), then re-check.

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Secondary intents covered: Find unclosed ``` code fences and language fences, Detect headings missing a space after #, Catch heading level jumps (e.g., H2 to H4), Identify empty link/image URLs like [x](), Spot likely unclosed link parentheses, Find trailing spaces and tab characters, Generate a quick report you can copy into an issue/PR, Triage Markdown problems before publishing (README, docs, notes)

FAQ

Does this Markdown checker upload my text?

No. The checks run in your browser and the tool does not send network requests.

What kinds of problems does it detect?

Common issues like unclosed code fences, heading formatting mistakes, empty/unclosed link URLs, trailing whitespace, and tab characters.

Will this guarantee my Markdown renders correctly everywhere?

No—Markdown flavors differ. This tool flags frequent mistakes, but your renderer (GitHub, GitLab, docs site) is the final authority.

Why does it warn about heading level jumps?

Skipping levels (H2 → H4) can hurt structure and accessibility. It’s a warning so you can decide if it’s intentional.

How do I fix “Heading missing space after #”?

Add a space after the hashes, e.g., # Title instead of #Title.

How do I fix empty links like [text]()?

Add a real URL inside the parentheses or remove the link markup if you don’t want it clickable.

Can I auto-format after checking?

Yes—use the related Markdown Formatter to normalize spacing and layout, then re-check here.