What this is
MarkdownLab is a growing collection of 29+ free, single-purpose Markdown tools — converters in both directions, an editor, utilities, and generators. Browse the full, always-current list on the all tools page. Each tool does one job well, rather than bundling everything into one configuration-heavy app.
Why everything runs client-side
Every tool on this site runs entirely in your browser's JavaScript engine — there is no upload step, no server-side conversion job, and no backend that ever sees your document. That's a deliberate design choice, not just a cost-saving one: Markdown documents frequently contain things people don't want leaving their machine — drafts, internal notes, credentials embedded in config snippets, unpublished writing. Doing the conversion locally means there's nothing to intercept, log, or leak on our end, because the data simply never reaches us. See the Privacy Policy for the specifics, including the one exception (the editor's localStorage autosave, which also stays entirely on your device).
A side effect of the client-side approach: most of these tools work offline once the page has loaded, and none of them have a file-size limit imposed by a server timeout — the only limit is what your own browser tab can hold in memory.
Open-source libraries and licenses
None of this is built from scratch. The conversions and editor are built on the following open-source libraries, each running entirely in your browser and none of them phoning home:
| Library | License | Used for |
|---|---|---|
| marked | MIT | CommonMark/GFM Markdown parsing, used by every Markdown-to-X tool and the editor's live preview. |
| DOMPurify | Apache-2.0 (dual-licensed MPL-2.0/Apache-2.0) | Sanitizes every rendered HTML output before it touches the page, so pasted or converted content can never execute a script. |
| Turndown | MIT | HTML-to-Markdown conversion, with the turndown-plugin-gfm plugin (also MIT) for GFM tables, strikethrough, and task lists. |
| docx | MIT | Generates real .docx files for Markdown to Word, entirely in the browser. |
| PapaParse | MIT | CSV/TSV parsing for CSV to Markdown and the table generator's import feature. |
| SheetJS Community Edition | Apache-2.0 | Reads .xlsx/.xls workbook data for Excel to Markdown, and writes it for Markdown to Excel. |
| Phosphor Icons | MIT | The icon set used throughout the interface. |
| next-themes | MIT | Light/dark theme switching, following your system preference by default. |
| mammoth | BSD-2-Clause | Converts uploaded .docx files to HTML for Word to Markdown and Google Docs to Markdown (pasting rich text still works without it). |
| html-to-image | MIT | Renders the Markdown to Image export card to a PNG, JPEG, WEBP, or SVG file, entirely in the browser. |
| Prettier | MIT | Formats Markdown (spacing, list and heading normalization, line wrapping) for the Markdown Formatter tool and the editor's Format button. |
The site itself is built with Next.js and Tailwind CSS. Each library above keeps its own upstream license text, which governs that library's use independent of this site's own Terms of Use.
Get in touch
Found a conversion bug, or have a tool you'd like to see added? See the Contact page.