What is a .xlsx file?
A .xlsx file is an excel 2007 spreadsheet. Its registered MIME type is application/vnd.openxmlformats-officedocument.spreadsheetml.sheet, which places it in the application or document family of formats.
Technically it is a specialised form of application/zip (the .zip format), so tools that understand that format can often read at least part of it.
XLSX is a binary format: the contents are not readable text, so opening it in a text editor shows scrambled characters.
XLSX file format details
| Extension | .xlsx |
|---|---|
| Format | Excel 2007 spreadsheet |
| MIME type | application/vnd.openxmlformats-officedocument.spreadsheetml.sheet |
| Category | Application or document |
| Text or binary | Binary |
| Based on | application/zip |
| File signature | None fixed |
| Registered with IANA | Yes |
| Other extensions | None |
How to open XLSX files
| Windows | XLSX files (Excel 2007 spreadsheet) are made by specific software. The reliable way to open one is with the program that created it; a generic viewer will only show raw data. |
|---|---|
| Mac | The same applies on a Mac: look for a Mac version of the program that makes XLSX files. |
| iPhone and iPad | Phones rarely open this type of file directly. The viewer above can show what is inside it without installing anything. |
| Android | The same applies on Android. The viewer above shows the first bytes of the file so you can confirm what it is. |
Convert XLSX files
TapToConvert converts XLSX files in your browser, without uploading them. Open the XLSX converter, or go straight to a conversion:
XLSX file FAQ
What is a .xlsx file?
A .xlsx file is an excel 2007 spreadsheet, with the MIME type application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.
How do I open a .xlsx file?
With the program that created it. The viewer on this page shows what is inside without installing anything.
Is a .xlsx file safe to open?
XLSX files hold data rather than programs, but any file from an unknown source can be crafted to exploit the software that opens it. Keep that software up to date. The viewer on this page only reads the bytes and never runs anything.
What is the MIME type of .xlsx?
application/vnd.openxmlformats-officedocument.spreadsheetml.sheet. Web servers send this type so browsers know how to handle the file.
Is XLSX a text or binary format?
Binary. Its contents are not readable as text.
File type facts come from the IANA media type registry, the mime-db project and the freedesktop.org shared MIME database.