Numbers can import delimited text into a spreadsheet. It can be a convenient opener for CSV exports on Mac, but interpretation of separators and cell values needs checking before you save or send the data onward.
Method 1: Use Finder
- In Finder, select a sample file such as export.csv.
- Press Command–I, or choose File → Get Info.
- Expand Open with and choose Numbers. If it is missing, choose Other and locate the installed app.
- Click Change All and confirm the macOS prompt.
- Double-click another file of the same type to check the new default.
Method 2: Manage associations with Pahkui
Pahkui lets you browse by app or by format. When setting up an editor for several file types, you can inspect the current defaults and review pending changes in one window. Requires macOS 14 or later.
- Open Pahkui, switch to Format, and search for the extension you need from .csv.
- Select Numbers. Use Choose another app if it is not listed.
- Review the pending association, click Apply changes, and confirm the new app in the macOS dialog.
The formats in this guide require Pahkui Pro, a one-time purchase for lifetime use. The manual Finder method does not require a purchase. See pricing

If the default app does not change
- If the table is not separated correctly, review Numbers’ import settings rather than repeatedly changing the opener.
- Use export when another app needs CSV; saving a Numbers document is a different output format.
- If Numbers is missing, confirm it is installed and can open the sample directly, then locate it with Other. If an extension is absent from the catalog, add the format in Pahkui. Changing an association does not add format support to the target app.
Common questions
Does a Numbers default turn CSV into a .numbers file?
No. It only chooses the app. Saving or exporting determines the resulting file format.
How do I restore the previous app for .csv?
Choose the previous app again in Finder or Pahkui and confirm the change. This updates the type association without deleting files. Use the Open With context menu for a one-time exception.