Convert Excel to Markdown (or CSV)

Turn .xlsx workbooks into Markdown tables you can paste anywhere — or flip one switch and get plain CSV, the most token-efficient format for sheet data. All conversion happens on your Mac.

How to convert a spreadsheet

  1. Drop the .xlsx into Milldown.Multi-sheet workbooks convert every sheet, each under its own heading.
  2. Choose your output: Markdown tables (readable) or CSV (compact).Options → Output → "Spreadsheets as CSV". Multi-sheet workbooks get clear per-sheet markers.
  3. Copy or save — CSV exports save as a proper .csv file.

Markdown table or CSV — which should you use?

ChooseWhen
Markdown tablesHuman readers: documentation, Obsidian notes, GitHub READMEs, anywhere the table should render.
CSV modeMachine consumers: AI prompts, data pipelines, re-import into other tools. In our measurements CSV uses about 39% fewer tokens than the same data as a Markdown table.

Honest note: for pure sheet data, Markdown tables are actually more token-expensive than CSV — all those pipes add up. That's exactly why Milldown offers both and shows the token count either way.

Details

Formulas convert as their last computed values. Cell formatting (colors, borders) is presentation, not content, and isn't carried across. Legacy .xls files: re-save as .xlsx first.

Try it on your own files

Milldown converts PDFs, Office documents, web pages, and scans into clean Markdown — entirely on your Mac. Free for 14 days.

Get Milldown for macOS

macOS 14+ · Apple Silicon · $39 one-time after trial (excl. VAT) · no subscription