Convert Excel (XLSX) to Markdown tables

POST /v1/convert converts an Excel workbook (.xlsx) to Markdown in one call. Each sheet becomes a ## <sheet name> heading followed by one Markdown table, in workbook order.

curl

curl -F "file=@figures.xlsx;type=application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" \
  https://api.flatmark.dev/v1/convert

The markdown field of the response:

## Q3
| Region | Revenue | Growth |
| --- | --- | --- |
| EMEA | 412000 | 0.08 |
| APAC | 260500 | NaN |

## Q4
| Region | Revenue |
| --- | --- |
| EMEA | 448900 |

Python: one chunk per sheet

import httpx

XLSX = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"

with open("figures.xlsx", "rb") as fh:
    resp = httpx.post(
        "https://api.flatmark.dev/v1/convert",
        files={"file": ("figures.xlsx", fh, XLSX)},
        headers={"X-API-Key": "YOUR_KEY"},  # optional
        timeout=60,
    )
resp.raise_for_status()
markdown = resp.json()["markdown"]

sheets = {}
for block in markdown.split("## ")[1:]:
    name, _, table = block.partition("\n")
    sheets[name.strip()] = table.strip()

for name, table in sheets.items():
    print(name, len(table.splitlines()) - 2, "rows")

Check the output

• The first row of each sheet becomes the table header. If a title sits above the real header, remove it before you upload.
• Empty cells come out as NaN, and empty header cells as Unnamed: 1 and so on.
• Formulas come out as the values Excel last saved. A formula that was never calculated comes out as NaN.
• Charts, images and formatting are dropped.

Next step

Convert a workbook in the browser, up to 4 MB and without an account.

FAQ

Does flatmark accept .xls files?

No. Only .xlsx is accepted, and .xls is rejected with an error (415). Excel, LibreOffice and Google Sheets can save a workbook as .xlsx.

What happens to empty cells?

Empty cells come out as NaN. Empty header cells come out as Unnamed: 1, Unnamed: 2 and so on.