Your files stay on your device

XLSX Reader and Writer: Inspect, Convert, Build Workbooks

Inspect a workbook (sheets, used ranges, formulas, merges), convert any sheet or range to CSV, TSV, JSON, HTML, or Markdown with dates and numbers formatted, and build an XLSX from CSV or JSON.
Excel workbookInput kindCSVJSONSheet name (optional)Build XLSX

- No recalculation. Formula cells ship their cached results, as stored by the app that saved the file.
- The writer is minimal on purpose: values, types, date serials, and sheet names; no styling, formulas, charts, or macros, ever.
- Reader: styling, charts, and macros do not survive conversion; number formats apply to table output through a bounded code subset.
- .xls (pre-2007 binary) is not a ZIP container and is refused by the signature check.
Nothing in yet

Paste, drop, or type to begin. Everything stays on this device.

load an .xlsx, pick a sheet, convert

Next door in Files

- DOCX reader (/files/docx)
- PPTX reader and slide PDF (/files/pptx)
- CSV studio (/config/csv)
All files tools (/files)

Canonical HTML: https://nutter.tools/files/xlsx
Markdown version: https://nutter.tools/files/xlsx/index.md
Plain-text version: https://nutter.tools/files/xlsx/index.txt
Agent index: https://nutter.tools/llms.txt