Add your XLSB file
Drop one or more .xlsb files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
XLSB to XLSX
Converting a .xlsb file to .xlsx extracts the document's content from its office package into a portable form. Free, private, and validated — the file never leaves your browser.
Private for supported formats — processed in your browser
Runs on your deviceConvert supported files
Drop XLSB files here
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.About converting Excel binary workbook to Excel workbook
Converting a .xlsb file to .xlsx extracts the document's content from its office package into a portable form. An .xlsb file is a Microsoft Excel workbook whose sheets are stored as binary BIFF12 records instead of XML. The packaging is the same ZIP as .xlsx, but each worksheet is a .bin part, which makes very large workbooks noticeably faster to open and smaller on disk.
An .xlsx file is a modern Excel workbook — a ZIP archive of SpreadsheetML XML parts describing sheets, shared strings, styles, and formulas. It has been Excel's default save format since 2007 and the de facto interchange format for tabular business data. For this route the practical draw is vast grid limits compared with the legacy .xls format and documented ZIP-of-XML anatomy — any ZIP and XML library can mine it, which is how in-browser conversion works here — balanced against date-as-serial-number storage causes subtle off-by-one and timezone bugs, which is worth knowing before you commit a large batch.
Why convert XLSB to XLSX?
The practical trigger for this conversion is usually a mismatch: with .xlsb, far less widely supported than .xlsx outside Microsoft's own tools. Switching to .xlsx buys you vast grid limits compared with the legacy .xls format, which is why it is the better fit for the standard vehicle for exchanging spreadsheets between organizations. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
XLSB vs XLSX at a glance
| Aspect | Excel binary workbook (.xlsb) | Excel workbook (.xlsx) |
|---|---|---|
| Format type | Text-based — characters and structure, so there is no visual quality loss | Text-based — characters and structure, so there is no visual quality loss |
| How it stores data | oOXML ZIP package whose worksheets are xl/worksheets/sheetN.bin rather than XML | xl/worksheets/sheetN.xml holds rows of typed cells; text cells usually point into xl/sharedStrings.xml to avoid repetition |
| Strongest at | very large models where .xlsx open and save times have become painful | the standard vehicle for exchanging spreadsheets between organizations |
| Weak spot | far less widely supported than .xlsx outside Microsoft's own tools | date-as-serial-number storage causes subtle off-by-one and timezone bugs |
| Metadata | docProps/core.xml and docProps/app.xml remain XML inside the package, so author and application metadata survive there even though the cells are binary | docProps/core.xml carries Dublin Core creator and date fields while docProps/app.xml records the generating application and company — both ride inside the ZIP |
Pick XLSX as the output
Select .xlsx in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if XLSX is selectable, the route is real and validated.
Convert on your device
Press Convert. The package is unzipped in memory and its XML content parsed locally; nothing is uploaded.
Verify and download
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid XLSX file. Outputs keep the original filename with the .xlsx extension.
XLSB to XLSX questions, answered
Will converting XLSB to XLSX lose quality?
There is no visual quality to lose — xlsb is text-oriented and xlsx is text-oriented, so the question is structural fidelity. Text, ordering, and basic structure are preserved; complex layout, embedded objects, and styling beyond the target's model are simplified.
Is it private to convert XLSB files here?
Yes — the .xlsb file is processed inside your browser tab and never uploaded. The package is unzipped in memory and its XML content parsed locally; nothing is uploaded. Close the tab and the file is gone from memory.
Where will the XLSX file work?
Excel 2007 onward, LibreOffice Calc, Google Sheets, and Apple Numbers all handle .xlsx, and nearly every data-processing library reads it. Support is equally solid on iOS and Android through the same vendors' apps.
Will the XLSX file be bigger or smaller than my XLSB?
It depends on the content: xl/worksheets/sheetN.xml holds rows of typed cells; text cells usually point into xl/sharedStrings.xml to avoid repetition. Convert one representative file first and compare before batch-processing a large set.
What happens to the metadata in my XLSB file?
In .xlsb, docProps/core.xml and docProps/app.xml remain XML inside the package, so author and application metadata survive there even though the cells are binary. Re-encoding through the browser pipeline does not carry embedded metadata into the output, which doubles as a privacy scrub — check the exported file if you specifically need tags preserved.