All About Excel Files (Types, Extensions, Open, Merge, Etc. )

What Are the Available File Types That Are Supported in Excel?

Excel supports 3 file formats. Their names, extensions, and details are in separate lists below.

1.1 Excel Files Format

Name Extension Details
Excel Workbook .xlsx The Excel 2010 and Excel 2007 default XML-based file format.
Excel Macro-Enabled Workbook .xlsm Stores Excel 4.0 macro sheets or VBA macro code.
Excel Binary Workbook .xlsb Excel 2010 and Excel 2007’s binary file format (BIFF12).
Excel Template .xltx For both Excel 2010 and Excel 2007, the default file format for an Excel template.
Excel Macro-Enabled Template .xltm Stores Excel 4.0 macro sheets or VBA macro code for template.
Excel 97-2003 Workbook .xls Excel 1997 and Excel 2003’s binary file format (BIFF8).
Excel 97-2003 Template .xlt Excel 1997 and Excel 2003’s binary file format (BIFF8) for template.
Microsoft Excel 5.0/95 Workbook .xls Excel 5.0/95’s binary file format (BIFF5).
XML Spreadsheet 2003 .xml File format for XML Spreadsheet 2003 (XMLSS).
XML Data .xml Data format in XML.
Excel Add-In .xlam The XML-based Add-In format for Excel 2010 and Excel 2007, which supports macros.
Excel 97-2003 Add-In .xla The XML-based Add-In format for Excel 1997 and Excel 2003, which supports macros.

1.2 Text Format

Name Extension Details
Formatted Text (Space delimited) .prn Lotus space-delimited format.
Text (Tab delimited) .txt Ensures that tab characters, line breaks, and other characters are properly understood when saving a workbook as a tab-delimited text file for usage on a different Microsoft Windows operating system.
Text (Macintosh) .txt Same as Text (Tab delimited) but works in the Macintosh operating system.
Text (MS-DOS) .txt Same as Text (Tab delimited) but works in the MS-DOS operating system.
Unicode Text .txt Worksheet is saved as Unicode text.
CSV (Comma delimited) .csv Enables the usage of a workbook on another Windows operating system by saving it as a comma-delimited text file.
CSV UTF-8 (Comma delimited) .csv Same as CSV (Comma delimited) but allows special characters.
CSV (Macintosh) .csv Same as CSV (Comma delimited) but works on the Macintosh operating system.
CSV (MS-DOS) .csv Same as CSV (Comma delimited) but works on the MS-DOS operating system.
DIF (Data Interchnage Format) .dif Format for Data Interchange.
SYLK (Symbolic Link) .slk Format for Symbolic Link.

Note: All formatting is lost when you save a workbook in text format.

1.3 Other File Formats

Name Extension Details
OpenDocument Spreadsheet .ods You can save Excel 2010 files so they can be opened in spreadsheet software like Google Docs and Calc that supports the OpenDocument Spreadsheet format.
PDF .pdf Portable Document Format (PDF).
XPS Document .xps This file format allows file sharing and maintains document formatting.

1.4 File Formats That Use Clipboard

The Microsoft Office Clipboard supports the following listed file formats. You can paste data from this clipboard to Excel easily.

Name Extension Details
Picture .wmf or .emf Format for pictures in Windows Metafile (WMF) or Windows Enhanced Metafile (EMF).
Bitmap .bmp Format for pictures in Bitmap format (BMP).
Formatted text (Space-delimited) .rtf Format for Rich Text (RTF).
Embedded object .gif, .jpg, .doc, .xls, or .bmp Format for Microsoft Excel objects.
Linked object .gif, .jpg, .doc, .xls, or .bmp Format for OwnerLink, ObjectLink, Link, or Picture.
Office drawing object .emf Format for office drawing object or Picture.
Single File Web Page .mht, .mhtml Format for Single File Web Page (MHT or MHTML).
Web Page .htm, .html Hypertext Markup Language (HTML).

1.5 File Formats That Are Not Supported in Excel

The file formats that are not supported in Excel are listed below with extensions and details.

Name Extension Details
Excel Chart .xlc File types for Excel 2.0, 3.0, and 2.x
WK1, FMT, WK2, WK3, FM3, WK4 .wk1, .wk2, .wk3, .wk4, .wks File formats for Lotus 1-2-3 (all versions)
Microsoft Works .wks File formats for Microsoft Works (all versions)
DBF 2 .dbf File formats for DBASE II.
WQ1 .wq1 File formats for Quattro Pro for MS-DOS.
WB1, WB3 .wb1, .wb3 File formats for Quattro Pro 5.0 and 7.0 for Windows.

1.6 How to Open or View Unsupported File Formats in Excel?

  • To open or view unsupported file formats in Excel, search file format converters online for file types that Excel does not support.
  • Then, export from that software into a file format that Excel supports.

2. Overview of Excel File Extensions

Each format and extension differs from others in different criteria.

2.1 Difference Between Xlsx Vs Xls format

In this section, you will learn the difference between .xlsx and .xls file formats.

  • See the difference in file size. The .xls file is larger than the .xlsx file.

Size difference between different excel files

  • The row and column numbers are also significantly different. The .xls file has a row limit of 65,536 (216) and 256 columns (IV).

Rows and columns limit of .xls files

  • Tthe .xlsx file has a row limit of 1,048,576 rows (220) and 16,384 columns (214) or column XFD.

Rows and columns limit of .xlsx files

Feature XLS (Excel 97-2003 Workbook) XLSX (Excel Open XML Workbook)
File Format Binary Open XML
File Extension .xls .xlsx
File Size Larger Smaller
Compatibility Older Excel versions may require a compatibility pack Widely compatible with modern Excel versions
Features May lack some advanced features available in newer Excel versions Supports all features introduced in Excel 2007 and later
Security Potentially higher security risks due to the binary format Improved security features with XML-based structure
Data Recovery More challenging Easier due to the XML-based structure

2.2 Difference Between Xlsx Vs Xlsb format

Learn the difference between .xlsx and .xlsb file format.

Feature XLSX (Excel Workbook) XLSB (Excel Binary Workbook)
File Format XML-based format Binary format
Storage Uses separate XML files within a compressed folder Uses a binary format
Human-Readability Human-readable, can be easily inspected Not human-readable, as it is in binary format
Compatibility Widely supported by various spreadsheet software and tools Supported by Microsoft Excel; may have limited support in third-party applications
File Size Tends to be larger due to XML-based structure Tends to be smaller due to binary format, potentially more efficient with large datasets
Performance Slower in some scenarios, especially with very large datasets May offer faster calculations and smaller file sizes in some cases, especially with complex calculations and large datasets
Use Cases Standard choice for general-purpose spreadsheet work Considered when dealing with very large datasets or when optimizing for performance within the Microsoft Excel ecosystem
Versatility Versatile for sharing data across different platforms May have limited compatibility outside of Microsoft Excel

2.3 How to Check Excel File Extension?

How to check Excel file extensions. It helps to determine the Excel spreadsheet.

  • Click on the File tab.
  • Click on the Save As pane to see the file extension in the marked box.
  • The file has a .xlsx extension.

Checking excel file extension

2.4 How to Change Excel File Extension?

  • Follow the steps above and click on the arrow beside the file extension.
  • You can change the file type from the dropdown menu.
  • Choose your desired extension and click on Save.

Changing excel file extension

2.5 How to Save Macro-Enabled Files in Excel?

  • Choose Excel Macro-Enabled Workbook(.xlsm) from the dropdown.
  • Click the Save icon.

Saving macro-enabled files in excel

3. How to Open Excel Files?

  • Select any Excel file on your PC.
  • Right-click on the file and select Open from the context menu.
  • Select Excel from the side menu.

Opening excel file

3.1 How To Open Multiple Excel Files At Once in One Click?

  • Put the files that you want to open with a click in a folder on your PC.

Keeping excel files in same folder

  • In Excel click on the File tab from the Excel ribbon.

Opening backstage menu from file tab

  • Select Options from the side menu bar.

Opening excel options

  • Go back to the folder and copy the address.

Copying excel files location address

  • Go to the Advanced >> General. Paste the address in At startup, open all files named input box.

Inserting excel files location address

  • If you open the Excel app, it will open the files in that folder automatically.


Opening multiple excel files at once in one click

Click on this image for a better view

3.2 How to Open Two Excel Files Side By Side?

  • Open two Excel files.

Opening two excel files

  • Go to the View tab of any of the Excel files.
  • Click the View Side by Side option in the Window group.

Selecting view side by side from view tab

  • You’ll see the files get positioned like the following image.

Viewing two excel files side by side

4. How to Combine/Merge Multiple Excel Files?

The following image shows that we have two Excel files in a folder named 1. January_Data and 2. February_Data.

Keeping two excel files in same folder

In 1. January_Data, we have Product ID, Product Name, Purchase Date, Price, and Payment Method of a few items for January.

Dataset of first excel file

You have another file named 2. February_Data contains similar data in the same format for February.

Dataset of second excel file

To merge these files into one Excel file, follow these steps:

  • In the first January_Data file, change the dataset into a table using the Ctrl+T shortcut.

Converting data into table

  • Select the table and rename it as Payment_Data.

Naming the data table

  • Do the same for the file February_Data.

Inserting same name for another data table

  • Open a blank Excel workbook and click on the Data
  • Go to Get Data >> From File >> From Folder.

Getting excel files data from folder

  • Select the New Folder and click on Open.

Opening the files containing folder

  • Click Combine and select Combine & Load from the dropdown menu.

Combine and load excel files

  • You’ll get your common table name, select that, and click on OK.

Selecting common table name data

  • The data in two Excel files will be combined into one Excel file.

Combining multiple excel files into one

5. How to Use Excel AutoSave?

5.1 How to Turn On AutoSave in Excel?

How to turn on the AutoSave feature in Excel.

  • Go to File >> Options >> Save.
  • In the Save section, under Save Workbooks check the tick mark on the AutoSave files stories in the Cloud by default in Excel.
  • Click the OK button.

Turning on autosave in excel

  • It will save the file automatically in the AutoRecover file location.

5.2 How to Change AutoSave Time in Excel?

  • Check the tick mark on the Save AutoRecover information every and set the time of your preference.
  • In the following image, we set the time to every 10 minutes.

Changing autosave time in excel

5.3 How to Turn Off AutoSave in Excel?

  • Click on the circle beside AutoSave on the Quick Access Toolbar.

Showing autosave turned on in excel

  • You’ll see color changing, which means it has been turned off.

Turning off autosave in excel

5.4 Where Are Excel AutoSave Files Stored?

  • Go to the File tab and click on Open.
  • Double-click on the shared Onedrive.

Double-clicking onedrive

  • It will open the window containing the AutoSaved files.

Autosave file location in excel

6. How to Recover Excel Files?

6.1 How to Recover Excel File After Crash?

  • Click on the File tab and then go to Open >> Recent >> Workbooks.
  • At the bottom, you will see Recover Unsaved Workbooks.
Recovering unsaved workbooks in excel

Click on this image to have a better view

  • Click on that and it will open a folder on your PC. You will get the crashed Excel files there.

Crashed excel file location in excel

6.2 How to Recover Corrupted Excel File?

  • Click on File >> Open >> Browse.

Opening browse folder in excel

  • Write the corrupted file name in the File name box. Change the file type to All Files.
  • Select Open and Repair from the Open dropdown menu.

Open and repair excel files

  • It will repair and open the corrupted file.

6.3 How to Recover Previous Version Of Excel File?

  • Click the File tab and select Info.
  • Click the Version History.

Opening version history in excel

  • You will see the previous versions of that file.
  • You can recover your desired file.

Selecting preferred version of excel file

6.4 How Do I Find Excel Backup Files?

  • Go to File >> Open >> Recent in Excel.
  • In the Workbooks click on the Recover Unsaved Workbooks.

Selecting recover unsaved workbooks in excel

  • The Document Recovery You will find the backup files there.

Document recovery option in excel

7. How to Reduce Excel File Size

7.1 How to Reduce Excel File Size Without Opening?

  • We have an Excel file named Excel Files.

Uncompressed excel file

  • We will select the file and right-click on it.
  • Click Properties from the context menu.

Opening properties from context menu

  • In the Excel File Properties window, click Advanced.

Opening advanced options

  • Then, in the Advanced Attributes window, turn on the Compress contents to save disk space check box and click OK.

Compressing contents from advanced attributes

  • As a result, you will see the compressed file icon on the Excel file.

Compressed excel file

7.2 How to Reduce Excel File Size Without Deleting Data?

  • Go to File >> Save As and change the file type to CSV UTF-8 (Comma Delimited) (*.csv).

Saving as csv excel file

  • You will see the file size reduced significantly.

Comparison of size between excel files

7.3 How to Determine What is Causing Large Excel File Size?

  • Click on the Review tab and select Workbook Statistics from the Proofing
  • It’s showing 3 sheets in Workbook Statistics. But only two sheets are visible. This means we have a hidden sheet in the workbook.

Checking workbook statistics

  • Right-click on any Sheet tab and select Unhide from the context menu.

Unhiding excel sheet using context menu

  • You will see a dialogue box with the title Unhide one or more sheets. Select the hidden sheets and Unhide them.

Unhiding selected sheet in excel

  • You can see the Sheet3 visible in the Sheet tab.

Hidden sheet visible in excel

7.4 How to Compress Excel Files for Email?

  • Select the file and right-click on it.
  • Choose Compress to ZIP file from the context menu.

Compressing excel file from context menu

  • You will get a zipped version of the same Excel file beside the main file.

Compressed zip excel file

8. How to Speed Up Excel?

8.1 How to Make Excel Open Faster?

  • Click the File tab and go to Options >> Advanced.
  • Select Use all processors in this computer.
  • This will make your Excel open faster.

Using all processors in the computer for excel files

8.2 How to Open Large Excel Files Without Crashing?

  • Open Excel Options from File >> Options.
  • Click the Add-ins, choose COM Add-ins and Go.

Opening COM add-ins option in excel

  • Uncheck all the Add-ins and click OK.

Unchecking all add-ins

  • It will open large files without crashing.

8.3 How to Stop Calculating Threads in Excel?

  • Open Excel Options by clicking on File >> Options.
  • Go to Formulas, and in Calculation Options, choose Manual. This will stop calculating threads in Excel.

Selecting manual calculation options in excel

9. How to Encode Excel Files?

9.1 How to Encode File to UTF-8 in Excel?

  • Click the File tab and go to the Backstage View.
  • Select Save As and choose CSV UTF-8 (Comma Delimited) (*.csv) file format.
  • Click on Save and the file will be encoded.

Encoding excel file to utf-8 format

9.2 How to Check Encoding of Excel Files?

  • Go to the Save As option and you can see the file extension.
  • You will know the encoding of Excel files.

Checking encoding of excel file

10. What to Do If  Excel Files Are Not Opening?

10.1 Why Are My Excel Files Not Opening?

  • You have an Excel file.

Excel file in a folder

  • Try to open it with Excel, it opens in Notepad.

Excel file opened in notepad

  • Right-click on the file and choose Open with >> Excel from the context menu.

Opening excel file using Microsoft Excel

10.2 Excel File Open But Not Visible

  • Open the Excel file, and it does not show any data.

Excel file open but not visible

  • Go to the View tab and click on Window, it will show the hidden workbook.

Viewing hidden window in excel

10.3 Excel File Opens Blank Grey Screen

  • Go to File and open Excel Options.
  • In the Advanced >> General section, uncheck the Ignore other options that use Dynamic Data Exchange (DDE) option and click OK.

Unchecking advanced excel option

  • You can open the file resolving the gray screen issue.

11. How to Protect Your Excel Files?

  • Click on the Review tab and choose Protect Sheet.

Protecting sheet in excel

  • Put a password in the input box.

Setting password to protect sheet

  • Reenter the password to confirm.

Re-entering password to protect

  • You can also Unprotect Sheet using the same way.

Unprotecting excel sheet


Note: We have used Excel for Microsoft 365 to prepare this article.

Available File Types Supported in Excel
  ⏵Excel Files Format
  ⏵Text Format
  ⏵Other File Formats
  ⏵File Formats That Use Clipboard
  ⏵File Formats Not Supported in Excel
  ⏵Open or View Unsupported File Formats
Overview of Excel File Extensions
  ⏵Difference Between Xlsx Vs Xls Format
  ⏵Difference Between Xlsx Vs Xlsb Format
  ⏵Check Excel File Extension
  ⏵Change Excel File Extension
  ⏵Save Macro Enabled File
Open Excel Files
  ⏵Open Multiple Files in One Click
  ⏵Open Two Files Side By Side
Combine/Merge Multiple Files
Using Excel AutoSave
  ⏵Turn On AutoSave
  ⏵Change AutoSave Time
  ⏵Turn Off AutoSave
  ⏵Where AutoSave Files Are Stored
Recover Excel Files
  ⏵Recover File After Crash
  ⏵Recover Corrupted File
  ⏵Recover Previous Version Of File
  ⏵Find Excel Backup Files
Reduce Excel File Size
  ⏵Reduce Excel File Size Without Opening
  ⏵Reduce File Size Without Deleting Data
  ⏵Determine Cause of Large Excel File Size
  ⏵Compress Excel File for Email
Speed Up Excel
  ⏵Make Excel Open Faster
  ⏵Open Large Files without Crashing
  ⏵Stop Calculating Threads in Excel
Encode Excel Files
  ⏵Encode file to UTF-8 in Excel
  ⏵Check Encoding Of Excel File
Excel Files Are Not Opening
  ⏵Excel Not Opening Files
  ⏵Excel File Open But Not Visible
  ⏵Excel File Opens Blank Grey Screen
Protect Your Excel Files

Excel Files: Knowledge Hub

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Maruf Hasan
Maruf Hasan

Maruf Hasan, a BSc Electrical & Electronic Engineering graduate from Ahsanullah University of Science & Technology, boasts over a year of service as an Excel & VBA Content Developer at Exceldemy. He authored 30+ insightful articles and offers solutions to diverse Excel challenges. Maruf's exceptional content reflects his passion for Microsoft Office, problem-solving, and writing. Committed to simplifying complex processes, he significantly contributes to Exceldemy and is deeply enthusiastic about continuous learning in Microsoft Office Suite and data... Read Full Bio

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