Excel Compressor: Reduce Excel File Size in Your Browser
This free tool makes .xlsx and .xlsm files smaller. It runs in your browser, so your file never leaves your device. Pick a level, press Compress, and download the result. Formulas, charts, and cell data stay the same. How much you save depends on what is in the file. In our tests, a workbook full of large pictures shrank by up to 90%. A very large workbook that was mostly cell data shrank by about 2%.
How do I compress an Excel file online for free, without uploading it?
Drop your file in the box above, pick a level, and press Compress. The tool does all the work inside your browser tab. No server receives your file. The tool is free, and you do not need an account.
- Drop your .xlsx or .xlsm file in the box, or click the box to choose it.
- Read the size chart. It shows which parts of the workbook take up space.
- Pick Safe, Balanced, or Maximum, then press Compress.
- Check the report, then download the new file. Your original stays as it was.
How do you reduce the file size of an Excel spreadsheet?
Find what makes the workbook big, then remove it. Microsoft lists five steps that work in most files. Work on a copy, because some steps cannot be undone.
- Save the workbook as an Excel Binary Workbook (.xlsb). Microsoft says this format usually gives a smaller file.
- Delete sheets you no longer use.
- Lower the picture quality. Go to File, Options, Advanced. Under Image Size and Quality, choose 150 ppi or lower.
- Compress the pictures. Select a picture, open Picture Format, and choose Compress Pictures. Clear “Apply only to this picture” to change them all.
- Stop saving the pivot cache. In a PivotTable, open PivotTable Analyze, then Options, then Data. Clear “Save source data with file.”
With step 5, the PivotTable needs its data source to refresh when you open the file.
How much smaller will my workbook get?
It depends on what is inside. Pictures give the biggest savings. Plain data gives the smallest. These are our test results.
| Test workbook | Level | Before | After | Saved |
|---|---|---|---|---|
| 20,000 rows, 1 chart, 3 large pictures | Safe | 20.90 MB | 20.88 MB | Under 0.1% |
| Same workbook | Balanced | 20.90 MB | 9.40 MB | 55.0% |
| Same workbook | Maximum | 20.90 MB | 2.18 MB | 89.6% |
| About 1 million rows of data, 3 pictures | Maximum | 140.55 MB | 125.94 MB | 10.4% |
| Very large, mostly cell data | Maximum | 394.12 MB | 386.45 MB | 1.9% |
How we tested: We built these files for the test. The cells hold random numbers, which pack poorly, so real files with repeated text may behave differently. We ran every test in Chrome on a computer with 2 processor cores. The 21 MB file took about 2 seconds. The 140 MB file took 77 seconds, and the 394 MB file took about 4 minutes. Your times will differ.
What do the three levels do?
- Safe repacks the file at the highest ZIP setting. It also removes the calculation chain and the preview thumbnail. Excel rebuilds the calculation chain when you open the file. Pictures stay as they are.
- Balanced does everything Safe does. It also shrinks any picture wider or taller than 1600 pixels down to 1600 pixels. JPEG pictures are saved again at lower quality. PNG pictures stay PNG.
- Maximum does everything Safe does. It shrinks pictures to 1024 pixels at most. PNG pictures with no see-through areas are saved as JPEG.
The tool keeps a new picture only if it is at least 5% smaller. Pictures keep their size on the sheet, but you will see less detail if you zoom in. JPEG pictures that carry a rotation tag are left as they are.
What stays the same after compression?
| Part of your workbook | What happens |
|---|---|
| Cell values and formulas | Unchanged. The tool compares your sheets, shared text, and styles byte for byte. |
| Sheets, charts, pivot tables | The count is the same before and after. |
| Macros in .xlsm files | The macro project is not touched. |
| Pivot caches | Not changed. |
| Pictures | Same count. Balanced and Maximum lower the resolution. |
| Your original file | Never changed. |
The report checks each item after every run. If a check fails, or the file is not smaller, the tool gives no download.
How can I reduce Excel file size without losing quality?
Your numbers, text, and formulas keep full quality at every level. Only pictures can lose detail. Choose Safe to leave pictures alone. Excel has the same limit. Microsoft says that discarding editing data and deleting cropped areas of pictures cannot be undone. Clearing unused formatting changes how empty cells look, not your data.
Why is my Excel file so large?
Most large files come from five things:
- Formatting or data far below your real data
- Large pictures
- A pivot cache saved with the file
- Many formulas, mostly whole-column references
- Hidden sheets and objects you forgot about
To check the first one, press Ctrl+End. Excel jumps to the last cell it thinks you used. If that cell is far past your data, Excel counts empty cells as used. Select the empty rows below your data, delete them, save, close, and reopen the file. The size chart in the tool shows which part of your file is biggest.
How are Excel files compressed?
A modern .xlsx file is already compressed. It is a ZIP package of XML files, with a separate XML file for each sheet. Excel also stores each different piece of text once in a shared table, so repeated labels take little room. The older binary .xlsb format stores data in another way, and Microsoft says it gives a smaller file. How much a compressor can save depends on what the file holds, mainly pictures and unused formatting.
Does saving as .xlsb make a workbook smaller?
Often, yes. Microsoft says the binary format is enough for most uses and gives a smaller file. Choose File, Save As, then Excel Binary Workbook (.xlsb). To make it your default, go to File, Options, Save. Some other programs cannot fully read .xlsb, and SharePoint may hide Save As, so save a local copy first.
| Format | How it stores data | This tool |
|---|---|---|
| .xlsx | ZIP package of XML files | Yes |
| .xlsm | Same, plus macros | Yes |
| .xlsb | Binary | Not yet |
| .xls | Older binary format | Not yet |
How do I reduce a workbook with many sheets and heavy formulas?
Sheet count matters less than what sits on each sheet. Start with the sheets that hold formulas.
- Replace finished calculations with values. Keep a backup, because the formulas are gone afterward.
- Avoid volatile functions such as OFFSET, INDIRECT, RAND, TODAY, and NOW where you can.
- Use tables instead of copying a formula down thousands of rows.
- Delete duplicate rules under Home, Conditional Formatting, Manage Rules.
- Clear formats below your data with Home, Clear, Clear Formats.
How do I compress an Excel file over 100 MB?
First, find out whether the file holds real data or extra weight. Check pictures, pivot caches, and the used range, and try .xlsb. We ran this tool on a 394 MB file in Chrome, and it finished. Browser memory differs from one device to another, so very large files can fail on weaker devices. If most of the file is real data, expect a small saving. Our 394 MB test shrank by 1.9%. Import only the data you need, as Microsoft advises for the Data Model.
What can I do with a 28.5 GB Excel file?
Excel is not built for a workbook that size, and compression will not make it practical. A sheet holds at most 1,048,576 rows by 16,384 columns. Keep the raw data in a database or in CSV files, and load only the part you need. If the file may be damaged, try Excel’s repair option first. Microsoft notes that a damaged workbook can use a lot of disk space.
Why does a large workbook take minutes to save?
The same things that make a file large also slow it down. Microsoft says unused formatting makes files grow fast and slows Excel. On Windows, run Clean Excess Cell Formatting from the Inquire tab. The tab is not in every edition. If you cannot see it, go to File, Options, Add-ins, choose COM Add-ins, press Go, and check Inquire.
Back up first. Microsoft says you cannot undo the cleanup, and in some cases the file gets larger. Also compress pictures and try .xlsb. No fix promises a set save time.
How do I stop my workbook from getting bigger again?
- Do not format whole rows or columns.
- Compress pictures before you add more.
- Turn off “Save source data with file” for pivot tables if you can refresh on open. The PivotTable cannot refresh until its data source is available.
- Press Ctrl+End after big edits to check the used range.
- Move old sheets into a separate archive workbook.
- Use tables instead of copied formulas.
How do I compress an Excel file for email, or to 10 MB?
Check the limit first. Gmail allows 25 MB per email on personal accounts and swaps larger attachments for a Google Drive link. Outlook’s default limit is 20 MB for internet email accounts and 10 MB for Exchange accounts. Work and school accounts can have different limits.
To reach 10 MB, start with Balanced. If the file is still too big, try Maximum. Then check the size.
What is the maximum size of an Excel file?
A sheet holds at most 1,048,576 rows by 16,384 columns. No fixed file size limit exists. In 64-bit Excel, memory is the limit. In 32-bit Excel, the program gets 2 GB of address space, shared with add-ins. Since Excel 2016, Large Address Aware lets 32-bit Excel use twice as much memory on 64-bit Windows.
Is my Excel file uploaded anywhere?
No. The compressor runs in your browser, and no request carries your file. You can check this yourself:
- Open your browser’s developer tools. Press F12, or right-click the page and choose Inspect.
- Open the Network tab.
- Compress a file.
- Look at the requests. None sends your workbook.
What are the best tools to compress large Excel files?
Pick by what matters for your file. Choose local processing for private data. Check the size limit for big files. Look for level controls if you want choice. This table shows what each site says on its own page (checked October 11, 2026).
| Tool | Where the file is processed | Size limit stated | Controls |
|---|---|---|---|
| This tool | In your browser | No fixed limit. Tested to 394 MB. | Three levels |
| ExcelTool.io | In your browser | 50 MB on the upload box | Four options |
| WeCompress | Uploaded, then deleted | 50 MB, one file at a time | None |
| YouCompress | Uploaded, deleted after a few hours | Not stated | None |
| ClipCompress | Uploaded, deleted after about 6 hours | 50 MB | None |
| Internxt | Uploaded | Not stated | None |
Common questions
Can I compress several files at once?
Not yet. The tool handles one file at a time.
Does it work on .xls files?
No. Open the file in Excel, save it as .xlsx, then compress it.
What about a password-protected file?
It cannot be opened here. Open it in Excel, remove the password, save it, and try again.
Do I need an account?
No. The tool is free and needs no sign-up.
More free Excel tools: Excel Sample Data Generator and Variance Calculator.