The short answer
- A NUMBERS file is an Apple spreadsheet document that stores tables and related spreadsheet content, with full opening and editing intended for Apple Numbers.
- On a Mac, open the file with Apple Numbers. Numbers can also open Excel .xls and .xlsx workbooks and delimited or fixed-width text files. If Numbers reports unavailable fonts, choose Format > Font > Replace Fonts and select replacements. On Windows or another computer without Numbers, ask the sender to use Numbers on a Mac to export and send a separate Excel or PDF copy.
- A NUMBERS file can be encrypted with a password, and Apple says a forgotten password cannot be recovered. Finder's Locked setting is not access control because anyone can unlock the spreadsheet. In a shared spreadsheet, editors can change or remove its password, and older shared versions may retain an earlier password or no password. The cited Apple documentation describes no executable macros or other active code in this format; its documented risks concern access-control limits, including loss of an unrecoverable password and editors changing a shared spreadsheet's password, rather than code execution.
Apple Numbers Spreadsheet (.numbers)
A NUMBERS file is an Apple Numbers spreadsheet document. Apple Numbers creates and opens files with the .numbers extension. The National Archives' PRONOM record includes .numbers among the extensions for modern iWork 14 documents and records that Pages, Keynote and Numbers share an underlying container structure. Because PRONOM publishes neither a MIME type nor a literal byte sequence for matching, the format is identified by its container structure in DROID 6 or later together with the .numbers extension.
Numbers can export a separate copy as PDF, Excel, CSV, TSV or Numbers ’09. Excel export maps Numbers tables or sheets to worksheets. CSV and TSV retain delimiter-separated cell values rather than the editable spreadsheet model and may create separate files for different tables. PDF uses a selected page layout and image quality. Large tables may prevent export to Numbers ’09.
How to open it
On a Mac, open the file with Apple Numbers. Numbers can also open Excel .xls and .xlsx workbooks and delimited or fixed-width text files. If Numbers reports unavailable fonts, choose Format > Font > Replace Fonts and select replacements. On Windows or another computer without Numbers, ask the sender to use Numbers on a Mac to export and send a separate Excel or PDF copy.
On a Mac, open the file with Apple Numbers. Numbers can also open Excel .xls and .xlsx workbooks and delimited or fixed-width text files. If Numbers reports unavailable fonts, choose Format > Font > Replace Fonts and select replacements. On Windows or another computer without Numbers, ask the sender to use Numbers on a Mac to export and send a separate Excel or PDF copy.
Numbers can export a separate copy as PDF, Excel, CSV, TSV or Numbers ’09. Excel export maps Numbers tables or sheets to worksheets. CSV and TSV retain delimiter-separated cell values rather than the editable spreadsheet model and may create separate files for different tables. PDF uses a selected page layout and image quality. Large tables may prevent export to Numbers ’09.
File safety
A NUMBERS file can be encrypted with a password, and Apple says a forgotten password cannot be recovered. Finder's Locked setting is not access control because anyone can unlock the spreadsheet. In a shared spreadsheet, editors can change or remove its password, and older shared versions may retain an earlier password or no password. The cited Apple documentation describes no executable macros or other active code in this format; its documented risks concern access-control limits, including loss of an unrecoverable password and editors changing a shared spreadsheet's password, rather than code execution.
An unknown sender, a name ending in two extensions, or contents that do not match the extension — check before you open it.
Converting it
Numbers can export a separate copy as PDF, Excel, CSV, TSV or Numbers ’09. Excel export maps Numbers tables or sheets to worksheets. CSV and TSV retain delimiter-separated cell values rather than the editable spreadsheet model and may create separate files for different tables. PDF uses a selected page layout and image quality. Large tables may prevent export to Numbers ’09.
Convert a copy, never the original, then compare quality, metadata, and layout against what you started with.
Common questions
What is an Apple NUMBERS file used for?
A NUMBERS file is a spreadsheet created and opened by Apple Numbers. It can contain tables and other spreadsheet content, and it uses the .numbers filename extension.
How do I open a NUMBERS file on a Mac?
Open the .numbers file with Apple Numbers on the Mac. Numbers is the application identified by Apple for creating and opening this format.
Why does a NUMBERS file show a missing-font warning when opened?
The spreadsheet uses fonts that are unavailable on the Mac. In Numbers, choose Format > Font > Replace Fonts, then select replacements for the missing fonts.
What happens when a NUMBERS file is larger than 500 MB?
Numbers normally saves a spreadsheet as one file, but a spreadsheet larger than 500 MB can be saved as a package—a collection of files that macOS displays as a single file.
Should I use a NUMBERS file or an Excel workbook?
Use NUMBERS when the spreadsheet will be opened and edited in Apple Numbers. Use an Excel export when the recipient needs an Excel workbook, while allowing for table or sheet mapping during export.
How do I convert a NUMBERS file to Excel?
In Numbers on Mac, export a separate copy in Excel format. Each Numbers table or each sheet must be mapped to worksheets, and changing the exported copy later does not change the original NUMBERS file.
What is lost when a NUMBERS file is exported to CSV or TSV?
CSV and TSV reduce spreadsheet content to delimiter-separated cell values rather than preserving the editable Numbers spreadsheet model. Numbers may create separate files for individual tables.
Is a password-protected NUMBERS file safe to share?
A password encrypts the spreadsheet and restricts opening to people who know it, but a forgotten password cannot be recovered. In shared spreadsheets, editors can alter or remove the password, and older versions may have an earlier password or none.
Does locking a NUMBERS file prevent other people from opening it?
No. Apple's Finder-style Locked setting is not access control because anyone can unlock the spreadsheet. Use password protection when access restriction is required.
Why can a package-form NUMBERS file be damaged during upload or email transfer?
Some web and email services do not accept packages, and Apple warns that packages can be damaged when emailed or uploaded through a browser to third-party cloud services. Apple recommends the single-file form for these transfers.
Related formats
Sources
PRONOM: Apple iWork Document, Version 14 (fmt/1441) · The National Archives (UK)
Open a spreadsheet in Numbers on Mac · Apple Support
Export to other file formats in Numbers on Mac · Apple Support
Save a large spreadsheet as a package in Numbers on Mac · Apple Support
Save a document as a package or a single file in Pages, Numbers, or Keynote on Mac · Apple Support
Password-protect a Numbers spreadsheet on Mac · Apple Support
Lock a Numbers spreadsheet on Mac · Apple Support