How to open and edit an .xlsx file on a Mac without Excel

The short answer: macOS can already show you what is inside an .xlsx file, and you have four practical ways to edit one without paying for Excel. Which one to pick depends on whether you need to keep the file byte-identical for someone else's tooling, or you only need to read a few numbers.

If you only need to look at the data right now, open the workbook in the browser viewer on this site. It parses the file in the page, so nothing is uploaded, and it takes about as long as a double-click.

The four options, compared

Ways to open an .xlsx workbook on macOS without Excel
Option	Editing	What it does to the file
Quick Look (select the file, press Space)	None	Nothing. It renders a preview of the first sheets and never writes.
Numbers (Apple)	Full, in Numbers' own model	Imports into a .numbers document. Exporting back to .xlsx rebuilds the file, so parts Numbers does not model are not preserved.
LibreOffice Calc	Full	Reads and writes .xlsx directly. It rewrites the whole package on save, so the bytes of untouched parts change.
Native Sheets	Cells, formulas, formatting, rows, columns and sheets	Rewrites only the parts it models and copies every other part of the original package through unchanged.

Quick Look and the browser viewer are read-only, which is the right answer more often than people expect. A large share of "I need Excel" moments are really "I need to read column F".

Reading a workbook without opening anything

Select the .xlsx file in Finder.
Press Space for Quick Look, or press Option-Space for a full-screen preview.
Use the sheet tabs at the bottom of the preview to move between sheets.

Quick Look renders what the file already contains. It does not recalculate formulas: what you see for a formula cell is the value the last program to save the file cached there. That distinction matters if someone sends you a workbook they edited in a tool that does not recalculate.

Checking a workbook in the browser first

The XLSX viewer on this site reads the ZIP container and the sheet XML in the browser tab. It shows every sheet, the cell values, the formula behind a cell when there is one, and it exports any sheet as CSV. There is no upload step and no account, so it is a reasonable way to check a file from a stranger before you open it in anything with more privileges.

What the viewer will not do

It reads; it does not edit or save. It shows cached formula results rather than recalculating them, and it does not render charts, images or conditional formatting. For editing on macOS you still need an app.

Editing without changing the rest of the file

Every .xlsx file is a ZIP archive of XML parts: one part per worksheet, plus shared strings, styles, and whatever else the producing application wrote, such as chart definitions, pivot caches, drawings and printer settings. When a spreadsheet application saves, it usually regenerates the whole package from its own in-memory model. Anything it did not model is gone.

That is the specific problem Native Sheets was built around. Its reader keeps the raw bytes of every part it opened. On save it regenerates only workbook.xml, the sheet parts, sharedStrings.xml, [Content_Types].xml and the workbook relationships, and copies everything else through byte for byte. How that works in detail is worth reading if you are the person who has to hand the file back.

Getting Native Sheets today

Native Sheets is free and has no third-party dependencies. Download it, unzip it, and drag the app to your Applications folder. It needs macOS 14 or later, on Apple Silicon or Intel.

The app is signed with a Developer ID and notarised by Apple, and the notarisation ticket is stapled to the bundle, so it opens on the first try with no trip through Privacy & Security. You still get the one prompt macOS shows for anything downloaded, which you answer once.

You can also build it yourself. This needs Xcode 26 or newer:

./Scripts/make_zip.sh "path/to/Native Sheets.app"
open "path/to/Native Sheets.app" your-workbook.xlsx

Common questions

Will opening a file in Numbers change it?

Opening does not. Numbers imports the workbook into its own document format; the original .xlsx on disk is untouched until you export back over it. The export is a rebuild, not an edit of the original package.

Can I edit an .xlsx file in the browser viewer here?

No. The viewer reads workbooks only. Editing and saving happen in the macOS app.

Do I need to be online?

The macOS app works on local files and has no account, no sync and no upload step. The browser viewer needs the page to load once; the parsing itself then runs in the tab.

Why charts and pivot tables disappear when you edit someone else's workbook
What is actually inside an .xlsx file, why a save in the wrong app strips charts, pivot caches and conditional formatting, and how to check whether your own workflow does it.
Will my formulas work? The functions Native Sheets evaluates, and the ones it does not
The complete list of the 91 spreadsheet functions Native Sheets evaluates, what happens to a formula it cannot evaluate, and how to test your own workbook before you rely on it.
XLSX viewer: open a spreadsheet in your browser
Open an .xlsx workbook in this browser tab, read every sheet, see the formula behind a cell, and export a sheet as CSV. The file is parsed on your device and is never uploaded.

Open a workbook in the browser