Drop a DOCX, spreadsheet, CSV, Jupyter notebook, PDF, or paste a URL — and get clean, portable Markdown in an instant. Every conversion runs 100% in your browser, with zero uploads.
Drop any file to convert to MarkdownDrag & drop · or paste text with Ctrl+V
Processing happens 100% in your browser — nothing is uploaded.
100% Local Processing — Your files never leave your device
Every conversion runs in your browser in a Web Worker, using plain JavaScript. Your files are never uploaded to any server.
Blazing Fast (INP-Optimized)
Heavy parsing is offloaded to Web Workers so the interface never freezes — even on large spreadsheets or PDFs.
Pristine Markdown Output
Battle-tested libraries like Turndown, Mammoth and SheetJS produce clean, portable Markdown you can trust.
Free & Open
No accounts, no paywalls, no tracking of your documents. The same engine also powers an embeddable iframe widget.
Privacy-First Processing
MD Convert is built on a single, non-negotiable principle: your documents never leave your device. Unlike typical online converters that upload your file to a remote server, process it there, and send the result back, MD Convert does all of its work inside your own browser tab.
When you drop a file, it is read locally with the browser’s FileReader API and handed to a dedicated Web Worker — a background thread that runs the parsing libraries (Turndown, Mammoth, SheetJS, pdf.js and others) entirely on your CPU. The generated Markdown is rendered back to the page without a single byte of your content touching the network. There is no upload step, no temporary server-side copy, and nothing to delete afterwards, because nothing was ever transmitted.
This architecture has three concrete benefits:
Confidentiality by design. Sensitive contracts, financial spreadsheets, and unpublished research stay on your machine — ideal for regulated environments where uploading data to a third party is prohibited.
Speed. Removing the upload/queue/download round-trip means most conversions complete in milliseconds, even offline once the page has loaded.
Transparency. The only optional network request is the URL-to-Markdown feature, which fetches a public web page through a stateless CORS proxy that stores nothing. Every other converter is provably offline.
Because the conversion happens on your side of the network boundary, the privacy claim is something you can check rather than something you have to take on trust: open your browser’s developer tools, watch the Network panel, and convert a file. No request carries your document, because there is no endpoint to receive it.
Frequently Asked Questions
Why is client-side conversion faster and safer than server-based tools?
It removes the two slowest parts of a traditional online converter — uploading your file to a remote server and waiting in that server's processing queue — and it removes the copy of your document that those steps create. MD Convert parses the file directly in your browser, so a typical DOCX or CSV converts in tens of milliseconds, usually before a comparable upload would even finish: there is no network round-trip, no cold-start latency, and no rate limiting, because your own CPU does the work. A server-based converter must accept the whole upload, hold it in memory or on disk, and stream the result back, which also imposes file-size caps and leaves your document sitting on someone else's infrastructure. Here it never leaves your device, memory use stays bounded and streaming, there is no arbitrary size limit, and the tool scales for free because every user brings their own compute.
How does MD Convert handle a massive 50MB PDF without crashing the browser?
It uses sequential page-by-page streaming. Instead of loading the whole document into memory at once (or extracting every page in parallel with Promise.all, which would keep all pages resident and trigger Out-Of-Memory crashes), the PDF engine processes exactly one page at a time inside a Web Worker. After each page's text is extracted it calls the page's cleanup routine and drops the reference, so the browser's garbage collector reclaims that memory before the next page loads. Peak memory therefore stays roughly constant — about one page's worth — no matter whether the PDF is 5 pages or 500. You see live 'page N of TOTAL' progress as it streams.
Does the converter work offline, and is my data ever uploaded?
Every file-based conversion runs entirely on your device with zero uploads, so once the page has loaded it keeps working even if your connection drops. The single exception is the optional URL-to-Markdown feature, which must fetch the remote page's HTML through a stateless CORS proxy that stores nothing — no other feature makes a network request with your data.
Which file formats can I convert to Markdown?
You can convert HTML, Word DOCX, Excel/ODS spreadsheets, CSV/TSV data, live web page URLs, Evernote/XML exports, YAML, Jupyter notebooks (.ipynb), and PDF documents. Each format has a dedicated, SEO-friendly converter page with tailored options.