Skip to content
Lizely

Excel to JSON Converter

Turn one selected worksheet from a local .xlsx file into a readable JSON download without uploading the workbook.

Privacy: your files never leave your device. All processing happens locally in your browser.

How to use

  1. 1.Choose one local .xlsx workbook no larger than 20 MB.
  2. 2.Select the worksheet whose first row contains unique field names.
  3. 3.Convert to JSON, download the file, and inspect the records before using them elsewhere.

About Excel to JSON Converter

Excel to JSON converts one worksheet from a local .xlsx workbook into a JSON file that you can inspect, download, or pass to another local workflow. The page runs in the browser tab. You choose a workbook, the browser reads its packaged spreadsheet data, and the tool creates a JSON Blob for download. Your workbook is not uploaded to a conversion server, queued for processing, or retained by this tool. This is useful when a spreadsheet is the handoff format but an API, script, static data file, or developer tool expects JSON records instead. The conversion makes a new download and never changes the workbook stored on your computer.

Choose a normal .xlsx workbook, then select the worksheet you want to export. The first non-empty row is treated as the field-name row. Every header must be non-empty and unique, because duplicate keys would otherwise overwrite data in a JSON object. Each following row becomes one JSON record. Empty cells become null. Stored text, number, and Boolean values are preserved as ordinary JSON values. The tool deliberately reads stored cell values only: it does not execute spreadsheet formulas, macros, external links, scripts, or embedded content. Formula cells therefore export their stored value rather than running a calculation in the browser.

This version intentionally has a narrow, visible scope. It accepts .xlsx OOXML workbooks, not legacy .xls files, macro-enabled formats, password-protected files, or cloud URLs. The selected worksheet must stay within 100,000 addressed cells. Before SheetJS reads the workbook, the page checks the classic ZIP directory, limits the upload to 20 MB, rejects unsupported Zip64 or multi-disk packages, and limits the declared expanded package size and entry count. Those limits reduce accidental browser memory pressure; they are not a promise that every small file is inexpensive to parse. A damaged, encrypted, oversized, or unsupported workbook stops with an error instead of producing a partial download.

JSON is a data representation, not a spreadsheet clone. Formatting, column width, conditional formatting, charts, images, comments, filters, print settings, workbook protection, named ranges, and formula source text are outside this export. Dates can remain the numeric value stored by the workbook because the tool does not guess locale or date intent. If you need formatting or a visual inspection before conversion, use an Excel viewer first. If the source does not have a clean header row, edit or prepare it in the spreadsheet before exporting; inventing field names would make the JSON harder to audit.

For a dependable handoff, choose the smallest relevant worksheet, check that the headers express stable field names, convert it, and open the JSON download once before sharing it with another system. Keep the original workbook as the source of record. This tool does not merge workbooks, infer nested objects, normalize values, validate a business schema, repair formulas, fetch remote spreadsheets, or guarantee that another application will interpret every JSON value the same way. It provides a transparent local export of the selected sheet's stored cell values within explicit browser safety limits.

Methodology & sources

Validate a bounded classic .xlsx ZIP before dynamically loading the locked SheetJS browser module; read stored worksheet values without formula execution; require unique non-empty headers; serialize one selected sheet to a local JSON Blob.

Frequently asked questions

Does this upload my workbook?
No. The selected .xlsx file is read and converted in the current browser tab.
Which worksheet is exported?
Choose one worksheet after opening the workbook. The tool exports that selected sheet only.
Are formulas or macros executed?
No. The tool reads stored cell values only and does not run formulas, macros, links, or embedded scripts.

Related tools

Developer Tools guides

View all