Reduce Excel File Size
Upload a large Excel file and reduce its size instantly. Choose between compress-only (preserves all formatting) or strip-formatting (maximum reduction). Your file never leaves your browser.
Drop your Excel file here
or click to browse — .xlsx, .xls, .xlsm, .xlsb
100% private — your file never leaves your browser
How to Reduce Excel File Size
Upload your file
Drag and drop your .xlsx or .xlsm file. The tool shows its current size before any changes are made.
Choose reduction mode
Select "Compress only" to shrink the file without any data changes, or "Strip formatting" to remove all colours, fonts, and borders for maximum reduction.
Download the smaller file
The tool shows the new file size and the percentage saved. Click download to save the reduced file.
Why Excel Files Get Large
Excel files can grow unexpectedly large for several reasons — most of which have nothing to do with the actual amount of data:
- Formatting applied to entire columns or rows: Selecting an entire column and applying a colour or font creates formatting entries for all 1,048,576 cells in that column, even if only 100 have data. This alone can add several megabytes to the file.
- Conditional formatting on large ranges: Complex conditional formatting rules across large ranges add significant overhead and can slow calculation as well as increasing file size.
- Hidden sheets with large datasets: Sheets you cannot see can still contain thousands of rows. Use the Spreadsheet Auditor to reveal hidden sheets before reducing.
- Embedded images and charts: Images are stored uncompressed inside the .xlsx ZIP container. Each chart also stores its underlying data in a separate XML file.
- Macro code (.xlsm): VBA macro code stored in vbaProject.bin can add significant size. If you no longer need the macros, use the Excel Macro Remover to strip them and convert to .xlsx.
- Poor default compression: Some Excel versions save .xlsx files with minimal ZIP compression. Re-saving with maximum compression can reduce size by 30–50% instantly.
Microsoft documents the official Excel file size reduction techniques including clearing excess formatting and removing unused styles.
Frequently Asked Questions
How much can it reduce my file size?
It depends on how the original file was saved. Files saved by Excel with default settings typically compress 20–50% with the compress-only option. Files with heavy formatting (many colours, conditional formatting, custom fonts) can reduce 40–80% with the strip-formatting option.
Will my data be changed?
No data is changed. The compress-only mode re-saves the exact same workbook with better ZIP compression. The strip-formatting mode removes visual formatting (colours, fonts, borders) but keeps every value, formula, and sheet.
Are my files uploaded to a server?
No. Everything runs in your browser using JavaScript. Your file never leaves your device.
Why is my Excel file so large?
Common causes: excessive formatting applied across entire columns or rows, hidden sheets with large data, conditional formatting on large ranges, embedded images and charts, and poor default compression. Some Excel versions save .xlsx files with minimal ZIP compression — re-saving with maximum compression can reduce the size by 30–50% with no other changes.
Will formulas still work after reducing?
In compress-only mode, yes — nothing changes except the compression level. In strip-formatting mode, all cell values and formula text are preserved, but conditional formatting rules and cell colour/font formatting are removed.
Related Excel Tools
Excel Macro Remover
Strip VBA macro code from .xlsm files — converts to smaller .xlsx files.
Spreadsheet Auditor
Find hidden sheets, volatile functions, and other issues before reducing.
Remove Blank Rows
Delete empty rows to reduce the workbook's used range and file size.
Duplicate Row Finder
Remove duplicate rows to cut down data volume before sharing.