XLSB to XLSX and CSV with a workbook loss report
Extract useful data from an Excel binary workbook while keeping the differences visible. Your original file stays local and unchanged.
Binary Workbook Bridge
Try the actual XLSB example with Unicode, leading-zero identifiers, date serials, formula-like text and a hidden sheet. The sample goes through the same binary reader as your file.
Supported scope: One XLSB up to 16 MiB; expanded archive up to 64 MiB; 1–32 sheets; used ranges up to 20,000 rows and 256 columns with 100,000 total grid cells. VBA and macro sheets are rejected. No password/decryption, recalculation, chart/pivot reproduction, full styling, XLS or XLSX input. Values-only extraction may omit unsupported binary records; retain the original.
Binary workbook
Required fields are marked with an asterisk.
Data handoff
Review your output, then save it to your device.
Make the next step clear.
Your findings, assumptions and next steps will appear here after you run the check.
Binary Workbook Bridge · https://workbooks.kitforma.com/ · KitForma
Real XLSB parsing and XLSX output
All, visible or named sheet selection
Formula, date and omitted-feature audit
Understand the evidence.
Focused guides explain the rules, the edge cases and the checks worth doing before you act.
Move XLSB data into an inspectable XLSX and CSV package
Keep useful cells while documenting the workbook features that do not travel.
Read the guide ↗Field guide / 02Understand formula caches and number preservation
Separate stored values from calculations and from their displayed formatting.
Read the guide ↗Field guide / 03Check hidden sheets, date systems and conversion limits
Make an intentional sharing decision before extracting a binary workbook.
Read the guide ↗Before you start
Does the XLSX keep working formulas?
No. The output deliberately contains saved values only. Readable formula text and its cached result are retained in the JSON report. Nothing recalculates formulas or refreshes links, so a cache may be stale or missing.
Are hidden sheets included?
The default includes all sheets. You can choose visible sheets or exact names. Original visibility is reported and retained where possible; the first selected output sheet is made visible because a workbook needs a visible sheet.
Will leading zeros and long numbers survive?
Text cells remain text in XLSX and JSON, including leading zeros. Numeric cells already contain binary floating-point values. The optional numeric-as-text export writes the readable stored number but cannot recover earlier rounding. CSV importers may infer numbers unless you explicitly choose text columns.
Can it process macros or protected files?
VBA projects, Excel macro sheets, encrypted containers and password decryption are outside this product. Nothing executes source macros. Remove macros or export a plain binary workbook in a trusted application before importing.
What do I lose in the conversion?
This is a data extraction. Charts, pivots, drawings, comments, defined names, external links, protection, merged layout and full styling are not reproduced. The report identifies detected archive features and retains original readable cell metadata.
Sources & assumptions
Formats, algorithms and supported features are documented below. Check the stated scope and inspect your output before using it.
- SheetJS cell model ↗
Stored values, formulas, caches and number formats are separate fields.
- SheetJS binary workbook support ↗
The pinned local SheetJS CE engine reads XLSB and writes XLSX.
- SheetJS macros ↗
VBA and macro sheets need explicit treatment; this tool rejects them.
- SheetJS date conventions ↗
Date serials and the workbook date system require interpretation.
Reviewed 2026-10-19. Read our methodology or report an issue.