Reduce Excel file size without changing what is inside
Drop in an .xlsx and get back a smaller copy whose contents are verified
identical, part by part. Every formula, value, image, format and setting is preserved
exactly. The file never leaves your computer.
Drop an .xlsx file here
Up to 100 MB. Processing happens in this tab.
What it does, and what it refuses to do
It rewrites the container, not the contents
An .xlsx is a ZIP holding XML, images and other parts. This tool
recompresses those parts. Every part keeps its name and its exact bytes. Nothing is
deleted, edited, minified, stripped or refreshed.
It proves it before offering a download
The smaller copy is reopened and compared against the original: same member list, same lengths, same decompressed bytes. If the comparison does not pass, or the copy is not actually smaller, you get nothing and your original is untouched.
It says no to files it has not been proved on
Legacy .xls, binary .xlsb, macro-enabled
.xlsm, encrypted and signed packages are rejected with a reason rather
than processed on a guess.
It is not a cleanup tool
It does not remove blank rows, unused styles, pivot caches, print settings or image metadata. Those change what a workbook does, and each one needs its own proof before it ships.
Common questions
- Why is my Excel file so large?
- An .xlsx is a ZIP holding XML, images and other parts, so its size is the sum of those parts. The usual culprits are the worksheet data itself, pivot caches, embedded images, and formatting applied thousands of rows past the last real one. This tool lists every part and what it costs, so you can see which one is responsible instead of guessing.
- Does shrinking change my formulas, values or formatting?
- No. Only the ZIP compression around each part changes. Every part keeps its name and its exact decompressed bytes, so formulas, cached values, number formats, images, charts, print settings and named ranges all come back identical. The copy is reopened and compared against the original before you are offered a download.
- How much smaller will my file get?
- It depends on how the file was written, and some workbooks will not shrink at all. Rather than promise a percentage, the tool reports the saving it actually achieved, and gives you nothing when the copy is not smaller than what you started with.
- Is my spreadsheet uploaded to a server?
- No. There is no upload and no server involved in processing. The page is static files and the work runs in WebAssembly inside your browser tab. You can confirm it by opening the Network tab in your developer tools while you shrink a file, or by disconnecting from the internet and shrinking one anyway.
- Does it work with .xls, .xlsm or .xlsb files?
- Not yet. Only conventional .xlsx packages are supported. Legacy .xls, macro-enabled .xlsm, binary .xlsb, and encrypted or digitally signed packages are refused with a reason rather than processed on a guess.
- Will a smaller file open or calculate faster in Excel?
- Not necessarily, and the tool does not claim it. Recompression changes how the file is packed on disk, not how much data Excel has to load and calculate once it is open. What a smaller file reliably helps with is storage, email attachment limits and sync time.
- How large a workbook can it handle?
- Up to 100 MB. The limit is the browser tab, which holds your file, a working copy, the engine memory and the result at the same time. Files over about 40 MB will be slower and the page will say so before it starts.
- Do I need to install anything or create an account?
- No. There is no install, no sign-up, no email and no watermark. Open the page and drop a file on it.
More on how the no-upload claim is enforced, and how to check it yourself, is on the privacy page.