XLSM to JSON Converter
Processing entirely on your device — large files may take a moment.
Convert tables to JSON when a website, app or API expects structured records with named fields. If your files are still in XLSM format, this page is the shortcut: XLSM is XLSX with a macro flag — the same OOXML package, permitted to store VBA. Macro-free sheets are ordinary XLSX data.
iLoveConverter processes everything locally on your computer, which makes it private and fast: no upload wait, no server storage, no limits. Add as many files as you like — batch conversion is built in.
How XLSM compares to JSON
| XLSM | JSON | |
|---|---|---|
| Structure | Multiple sheets | Trees of objects and arrays |
| Types / schema | Typed cells + formulas | Six native types |
| Compatibility | Excel 2007+, LibreOffice, Sheets | Universal, machine-first |
| Best for | Finance, analysis, models | APIs, app data, config-as-code |
How to convert XLSM to JSON
- 1
Select your files
Drag & drop your XLSM files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to JSON". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted JSON file individually, or grab everything at once as a ZIP archive.
About the XLSM 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 JSON format
JSON (RFC 8259, popularized by Douglas Crockford) is the lingua franca of program data. It has exactly six types — string, number, boolean, null, array, object — nested into trees, and every language on earth parses it natively. REST APIs, NoSQL documents, browser configuration, package manifests: if software talks to software, JSON is usually the sentence.
The spec is deliberately strict: double quotes only, no trailing commas, no comments. That rigidity makes parsers trivial and interop reliable, but it also makes JSON awkward for hand-edited config (people bolt comments on and break parsers) and its 1:1 text mapping keeps large files heavier than binary alternatives.
+ Strengths
- ✓Native parsing in every language
- ✓Six clear types, nesting as deep as needed
- ✓The default of APIs and modern tooling
! Limitations
- −No comments — poor fit for hand-edited config
- −Strict syntax: trailing commas and single quotes break it
- −Verbose; large files parse slowly
Why convert XLSM to JSON?
There is a concrete reason this conversion exists: Heavier and less diff-friendly than CSV JSON sidesteps that — Native parsing in every language If that is your situation, the tool above settles it in seconds, entirely on your device.
Frequently asked questions
Is this XLSM to JSON 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.
Is there a file size limit for XLSM to JSON?
The only limit is your device's memory, since nothing is uploaded. Files up to a few hundred megabytes work fine on a modern desktop browser; very large files simply take a little longer.
Are formulas, styles or multiple sheets converted?
No — this conversion extracts the data itself into JSON. Formulas are exported as their current values, styling is not carried over, and multi-sheet workbooks convert sheet by sheet. For full fidelity between spreadsheet formats, exchange within the same tool family.
Is my data safe here?
Yes. The conversion is plain JavaScript running in your tab: the data is parsed and re-serialized in memory, never sent anywhere, and disappears when you close the page.