Markdown Formatter & Linter
Check Markdown before you publish. Review safe formatting fixes and structural issues locally — nothing is uploaded.
Paste Markdown, import a local file, or try the README example. Safe fixes are never applied until you review them.
Review
Paste Markdown, import a local file, or try the README example to begin.
Preview is rendered locally and safely. It shows selected safe fixes without applying them to your input.
Format Markdown without losing control
MarkdownMaster checks common spacing, list, heading, and code-fence issues in your browser. When a change is safe and predictable, you can review it in a line-by-line diff before applying it. When a decision depends on your document’s meaning, the tool flags it for review and leaves the choice to you.
What this online Markdown formatter checks
Use this formatter before you publish a README, API reference, technical note, or release update. It can normalize heading and list spacing, remove accidental whitespace, replace tabs outside code blocks, reduce extra blank lines, and add a final newline. It also highlights structural issues that need an author’s judgment.
| Safe fixes you can review | Checks that need your decision | What this tool does not do |
|---|---|---|
| Heading and list spacing, extra blank lines, accidental trailing spaces, and final newlines. | Heading hierarchy, duplicate headings, code language labels, image alt text, and possible link syntax problems. | It does not rewrite prose, test remote links, upload files, or guarantee every Markdown renderer behaves the same way. |
Use it before you publish documentation
Start with a practical structure, then check formatting before you publish. Use a template for a GitHub README, API documentation, or release notes, and return to the Markdown editor when you need a live preview.
Markdown formatter FAQ
Does this formatter upload my Markdown?
No. Markdown is processed locally in this browser. MarkdownMaster does not upload your document, file name, or formatting results to a server.
Which fixes are safe to apply automatically?
Only predictable formatting changes are offered as selected safe fixes. Heading hierarchy, duplicate headings, code language labels, image alt text, and possible link problems stay review-only because they depend on your document’s meaning.
Will this Markdown linter rewrite my writing?
No. It does not rewrite prose, test remote links, or claim that every Markdown renderer will behave the same way. It focuses on explicit formatting checks you can review.
Private by design
Your Markdown is processed in this browser. Optional anonymous analytics are disabled unless you allow them and never include your Markdown text.
Your content is processed locally in this browser. Nothing is sent to a server.
Built for a practical Markdown workflow
Use this focused tool for a single task, then continue editing in MarkdownMaster when you need live preview, syntax highlighting, or a full writing workspace.