XLSX to GZ Converter
Processing entirely on your device — large files may take a moment.
Excel Spreadsheet and Gzip Compressed File exist for different jobs: XLSX is the modern Microsoft Excel workbook format. It stores multiple sheets with values, styles and charts, and opens in Excel, WPS Office, Numbers and Google Sheets. Unpack a .gz into a normal file or repack it as ZIP/TAR when the receiving tool does not understand gzip.
This converter runs entirely in your browser using WebAssembly — your files never leave your device, nothing is uploaded, and there are no watermarks, sign-ups or queues. Drop in several files at once to convert them as a batch.
How to convert XLSX to GZ
- 1
Select your files
Select your XLSX file.
- 2
Convert instantly
The file bytes are gzip-compressed in place — the same archive your server or build tool produces, made locally.
- 3
Download results
Download the .gz file — ready to upload, serve or attach.
About the XLSX format
XLSX is the modern Excel workbook (default since Excel 2007, same OOXML zip-package idea as DOCX). One file can carry multiple sheets, typed cells, formulas that recalculate, charts, conditional formatting and pivot caches — a small application, not just a table. LibreOffice, Google Sheets and WPS open it natively, and server-side libraries can read and write it without Excel installed.
Being a spreadsheet program's file, it is a poor plain-data exchange format: formulas reference cell positions that break when rows are reordered, hidden sheets and cached values surprise consumers, and the zip package is heavier than CSV. For analysis and finance it is the right tool; for pipelines, export the CSV.
+Strengths
- ✓Multi-sheet with formulas, charts and formatting
- ✓Typed cells and recalculation
- ✓Opens natively across the office ecosystem
!Limitations
- −Heavier and less diff-friendly than CSV
- −Formulas tie data to cell positions
- −Hidden state (sheets, caches) surprises downstream tools
About the GZ format
A .gz file is one file squeezed by gzip — not an archive. kernel.org tarballs are “tar inside gz”, but plenty of logs, JSON dumps and CSV exports travel as plain .gz. Opening one means decompressing it back to the original bytes.
Repacking into ZIP or TAR gives the decompressed file a container that every GUI tool opens without a second thought.
+Strengths
- ✓Everywhere on Linux and macOS
- ✓Fast, well-understood compression
- ✓Streams natively from any tool
!Limitations
- −Single file only — no directory tree
- −No encryption or integrity metadata
Why convert XLSX to GZ?
Think of it as moving your file to the container that fits the job. Heavier and less diff-friendly than CSV GZ works differently: Everywhere on Linux and macOS If any of that sounds like your task, run the conversion — it takes seconds and nothing leaves your device.
Frequently asked questions
Is this XLSX to GZ converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
What about special characters and non-English text?
Everything is handled as UTF-8. When you export CSV for Excel, a UTF-8 BOM is included automatically so Chinese, Japanese, Korean and accented characters display correctly on both Windows and macOS.
What about folders and directory structure?
The full directory tree is preserved: folders stay folders, and deep paths arrive exactly as they were packed in the XLSX file.
Are the files inside my XLSX archive modified?
No. Contents are unpacked in memory and repacked into GZ byte-for-byte — the conversion changes the container, never the files inside it.