Pick a format below to open its dedicated converter. File conversions run in your browser without uploading the source file; URL conversion fetches public page content through our proxy.
100% Local Processing — Your files never leave your device
File parsing stays in your browser and your files are not uploaded. Worker-backed formats run in a background thread; DOM-dependent formats parse locally in the tab.
Blazing Fast (INP-Optimized)
PDFs, spreadsheets, notebooks and supported text formats use Web Workers for parsing. DOM-dependent formats such as DOCX, HTML and XML run locally on the main thread.
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.
MD Convert is built on a single, non-negotiable principle: your local files are not uploaded for conversion. Unlike typical online converters that upload your file to a remote server, process it there, and send the result back, MD Convert does its file parsing in your browser.
Each converter page reads the file you select locally with the browser’s FileReader API and hands it to a dedicated Web Worker where supported, a background thread used by formats such as PDF and spreadsheets. DOM-dependent formats including DOCX, HTML and XML parse locally in the browser tab. The source file is not sent to a conversion server. URL conversion is the exception to fully local network activity: it fetches public page content through the stateless proxy.
This architecture has three concrete benefits:
Local file handling. File-based conversion does not upload the source file to a conversion server. Follow your organization's policies for sensitive or regulated documents.
Responsive processing. Worker-backed parsers process in a background thread. DOM-dependent formats run on the main thread, and processing time depends on the file and device.
Transparency. Local file conversions do not send the source file to a server. URL-to-Markdown fetches public page content through a stateless CORS proxy; see the privacy policy for the data-flow details.
Because file parsing happens in your browser, 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 file in file-based conversions. URL conversion does make a proxy request for the public page content.
Frequently Asked Questions
Why is client-side conversion faster and safer than server-based tools?
For file-based conversions, the source file is read locally rather than uploaded to a conversion server, so there is no upload-and-download round trip or server-side conversion queue. Worker-backed formats parse in a background thread; DOM-dependent formats parse locally on the main thread. Processing time and memory use depend on the format, file, browser and device, so large inputs may take longer or use substantial memory. The URL converter is different: it requests public page content through the site's proxy, but does not upload a local file.
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. Open the PDF to Markdown converter to try it.
Does the converter work offline, and is my data ever uploaded?
File-based conversions parse on your device without uploading the source file. Some parser code is loaded on demand, so an internet connection may be needed the first time you use a format. The URL converter is different: it fetches public page HTML through a stateless proxy. See the privacy policy for the full data-flow details.
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 its own converter page, listed under Dedicated Converters on this page.