How to Reduce File Size in Excel or PowerPoint

Microsoft Excel and PowerPoint have become irreplaceable work companions in most business environments.

Despite their impressive value, users often encounter painpoints, one of which is the excessive size of files. This issue can lead to multiple problems:

• Slowed work processes, negatively impacting productivity
• Long saving times, especially when files are on a network and need to be uploaded with each save
• Inability to email files to colleagues or clients due to messaging application size limits

To maintain high productivity and avoid these painpoints, you can leverage several techniques to reduce the size of your Excel workbooks and PowerPoint presentations.

How to Reduce the Size of Excel Files

The following techniques will help you minimize the file size of your Excel workbooks. You may use all of them or select the methods best suited for your project. Compare the results with the initial data to see the impact.

1. Eliminate Unnecessary or Duplicate Data

This is one of the simplest and most effective ways to reduce file size. If your Excel workbook contains content that isn’t useful, consider removing it or storing it in a separate file on your PC.

Typically, unnecessary data includes:

• Unused columns in a database, often caused by over-extracting data from business applications
• Duplicate data, usually a sign of poor structure. To optimize file size, learn the key principles for properly [structuring an Excel workbook]{.ul} .

2. Remove Unnecessary Formulas

Cells containing formulas take up significantly more space than those with simple values. If your data won’t change and formulas have become unnecessary, convert them to values for a substantial size reduction. Consider using PivotTables instead of formulas, as some tips below will help keep PivotTable size under control.

Tip: Always keep a version of your file with the original formulas in case you need them later.

3. Duplicate PivotTables Instead of Recreating Them

When you create a PivotTable in Excel, an invisible cache of your data source is generated, which can significantly increase file size. If you create multiple PivotTables from the same data source, the amount of cached data will grow unnecessarily.

Instead of creating PivotTables from scratch, copy and paste an existing PivotTable, then edit the fields for your new needs. This way, all PivotTables will use the same cache, limiting file size growth.

4. Keep Source Data Outside Your Workbook Using Power Query

Even with just one cache for your PivotTables, you’re still duplicating data in your workbook. To further reduce file size, keep the source data in a separate file and use Power Query to load it only into the PivotCache or PivotCharts.

This approach allows you to have one file for the source data and another for reports and charts, resulting in a smaller overall file size.

5. Optimize Images

If your Excel or PowerPoint file contains pictures, you likely have significant potential for file size optimization. Here are two methods to reduce picture sizes:

1. Use the built-in compression tool in PowerPoint, Excel, and Word:
   • Select a picture
   • Go to the “Picture Tools” / “Format” tab
   • Click “Compress Pictures”

Advantages:

• Quick and simple to use
• Allows compression of all pictures at once
• Enables removal of cropped areas (if no longer needed)

Disadvantages:

• Compression is not optimal
• May result in visible quality loss

2. Use a specialized online tool like [ImageOptim]{.ul} to compress pictures without visible quality loss.

6. ZIP Your File

A time-tested technique for compressing Excel files is zipping them. This immediately reduces file size, making it easier to share via email. Recipients can access the file by unzipping it on their desktop.

7. Remove Data Formatting

Data formatting can impact file size. Try to avoid over-formatting your spreadsheets. To remove all formatting in your selection:

1. Go to the “Home” tab
2. Click the “Clear” menu (the rubber icon)
3. Select “Clear Formats”

Avoid using conditional formatting on a large scale, as it can also add to file size.

8. Save Your Workbook as an .XLSB File

Saving your file as “.XLSB” instead of “.XLSX” can significantly reduce its size and allow for faster opening and closing times. However, use this format wisely, as there are some drawbacks:

• You won’t see if the file contains macros (unlike XLSM format)
• Most third-party applications can’t read XLSB files
• Power Query doesn’t work with XLSB

To save your file as .XLSB:

1. Press F12 or go to “File” / “Save As”
2. Change the “Save as type” to XLSB

9. Remove PivotTables Cache

By default, Excel saves the PivotTable cache when you save your file. To reduce file size, you can save the workbook without saving the cache:

1. Right-click any PivotTable in your workbook
2. Click “PivotTables Options”
3. Go to the “Data” tab
4. Uncheck “Save source data with file”
5. Ensure “Refresh data when opening the file” is checked

10. Analyze Spreadsheet Components’ Size

To identify which parts of your spreadsheet are taking up the most space:

1. Rename your file to change the extension “.xlsx” to “.zip”
2. Unzip the file
3. Open the “worksheets” folder and compare the size of each worksheet
4. Focus your optimization efforts on the largest components
5. When finished, change the extension back to “.xlsx”

By combining these techniques, you should be able to significantly reduce the size of your Excel files and improve their performance.

How to Reduce the Size of PowerPoint Files

Similar to Excel files, you may need to share your PowerPoint presentations with others. To reduce PowerPoint file size, you can apply many of the same techniques described above, along with some PowerPoint-specific methods.

1. Compress Pictures

Large image files are often the primary reason PowerPoint files grow quickly. To compress pictures directly in PowerPoint:

1. Select a picture and go to “Picture Format”
2. Click “Compress Pictures”
3. Select the desired picture quality
4. Check “Delete cropped areas of pictures” unless needed
5. Apply to one picture or all at once

For better results, use online tools to reduce picture size without compromising visual quality.

2. Keep Videos Outside the Presentation

Videos can have a huge impact on file size. While you can compress videos similarly to pictures (click “File” and “Compress media”), they often remain too large to manage effectively within the presentation.

Consider keeping videos outside your presentation by hosting them on a video platform like YouTube or storing them in a separate local file.

3. Clean the Slide Master

PowerPoint’s slide master can become bloated when pasting slides from other presentations, as it imports their masters as well. This can result in thousands of unused master slides, dramatically increasing file size.

Use the [Clean]{.ul} feature of the Power-user add-in to remove all unused master slides and significantly reduce file size.

4. Remove Hidden or Unnecessary Slides

Review your presentation for hidden or unnecessary slides and remove them to reduce file size.

5. Zip the File or Save as PDF

Zipping your PowerPoint file can provide a significant size reduction. Alternatively, if the recipient doesn’t need to edit the presentation, consider saving and sending it as a PDF.

6. Avoid Embedding Files

While embedding files like Excel spreadsheets or Word documents in your presentation can be convenient, it increases file size. If size optimization is crucial, keep these files separate.

7. Avoid Pasting Charts from Excel

When you copy a chart from Excel, the entire workbook is pasted into your presentation, rapidly increasing file size. Instead:

• Create charts directly in PowerPoint
• Paste charts as pictures or linked pictures

8. Analyze Presentation Components’ Size

Use the same technique described in Excel tip #10 to identify which slides and elements are taking up the most space in your PowerPoint file. Focus your optimization efforts on these components for maximum impact.

Final Words

By combining these tips, you should be able to dramatically reduce the size of your Excel and PowerPoint files, making them easier to email and faster to open.