---
title: ".xlsx file — what it is and how to open it"
description: "A .xlsx file is an Excel Workbook (Open XML). The standard Excel spreadsheet since 2007, with a million-row limit per sheet. How to open one on Windows, macOS and Linux, and what to convert it to."
url: https://atoneplace.net/file/xlsx/
site: "At One Place"
---

# .xlsx files

**.xlsx file: Excel Workbook (Open XML)**

The standard Excel spreadsheet since 2007, with a million-row limit per sheet.

## What opens a .xlsx file

- **Windows:** Microsoft Excel, LibreOffice Calc, WPS Office
- **macOS:** Microsoft Excel, Numbers (built in), LibreOffice Calc
- **Linux:** LibreOffice Calc, OnlyOffice, Gnumeric
- **In a browser:** Google Sheets, Excel for the web

## What a .xlsx file is

XLSX is the Office Open XML spreadsheet format: a zip of XML parts holding sheets, formulas, charts and formatting. It caps out at 1,048,576 rows and 16,384 columns per sheet, which is why very large data sets end up as CSV or Parquet instead. Google Sheets, LibreOffice Calc and Numbers all open it; complex formulas, pivot tables and conditional formatting are where non-Excel apps drift.

## Converting it

A .xlsx file is commonly converted to .csv, .pdf, .xls, .ods or .json. It is a binary format, so a text editor will show unreadable characters rather than its contents.

## Details

- **Extension:** .xlsx
- **Full name:** Excel Workbook (Open XML)
- **Category:** Documents
- **MIME type:** application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
- **Created by:** Microsoft
- **Format:** Binary

## Common questions

### How do I open a .xlsx file?

On Windows use Microsoft Excel; on macOS use Microsoft Excel; on Linux use LibreOffice Calc. The standard Excel spreadsheet since 2007, with a million-row limit per sheet.

### What is a .xlsx file?

Excel Workbook (Open XML). XLSX is the Office Open XML spreadsheet format: a zip of XML parts holding sheets, formulas, charts and formatting. It caps out at 1,048,576 rows and 16,384 columns per sheet, which is why very large data sets end up as CSV or Parquet instead.

### Can I convert a .xlsx file?

Yes. It is usually converted to .csv, .pdf, .xls, .ods or .json, either by exporting from one of the programs listed above or with a format converter.

## Related pages

- [.pdf — Portable Document Format](https://atoneplace.net/file/pdf/)
- [.docx — Word Document (Open XML)](https://atoneplace.net/file/docx/)
- [.pptx — PowerPoint Presentation (Open XML)](https://atoneplace.net/file/pptx/)
- [.txt — Plain Text File](https://atoneplace.net/file/txt/)
- [.doc — Word Document (legacy binary)](https://atoneplace.net/file/doc/)
- [.xls — Excel Workbook (legacy binary)](https://atoneplace.net/file/xls/)
- [.ppt — PowerPoint Presentation (legacy binary)](https://atoneplace.net/file/ppt/)
- [.md — Markdown Document](https://atoneplace.net/file/md/)
- [.rtf — Rich Text Format](https://atoneplace.net/file/rtf/)
- [.pages — Apple Pages Document](https://atoneplace.net/file/pages/)
- [.odt — OpenDocument Text](https://atoneplace.net/file/odt/)
- [.eml — Email Message](https://atoneplace.net/file/eml/)

## Sources

- Media Types Registry — IANA (https://www.iana.org/assignments/media-types/)
- Official vendor product documentation — At One Place (/about/)