Free Online Tool

Excel to JSON Converter

Convert your Excel (XLS, XLSX) and CSV spreadsheets into structured JSON data. Configure arrays, objects, and nested fields with advanced parsing options.

File Upload
Upload your Excel or CSV file. All processing happens locally in your browser.

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Advanced Options
Configure JSON output format

Converts "address.city" headers into nested objects

Converts numeric strings to Numbers, and boolean strings to true/false.

Output Excel serial dates directly instead of ISO date strings.

Features

Everything you need to convert Excel files to JSON

Local Processing

All conversion happens in your browser. Your files never leave your device — 100% private.

Multi-Sheet Support

Select and convert specific sheets from multi-sheet workbooks into structured JSON output.

Nested JSON

Automatically convert dot-notation headers like "address.city" into deeply nested JSON objects.

Flexible Output

Choose from flat arrays, object dictionaries, or wrapped root objects to match your data needs.

Smart Type Parsing

Auto-detect and convert numbers, booleans, and dates from string values in your spreadsheet.

No Installation

Works directly in your browser. No plugins, downloads, or software needed.

How to Convert Excel Files to JSON

Excel to JSON Converter is a free, privacy-first online tool designed to transform Excel spreadsheets and CSV files into structured JSON data. No login or registration needed — just upload your file, configure your options, and download the JSON output. Whether you need arrays, objects, or nested structures, our tool handles it all — directly in your browser with zero uploads to any server.

What Is Excel to JSON Converter?

Excel to JSON Converter is a web-based application that converts Excel files (XLS, XLSX) and CSV files into JSON format without installing any software. Unlike API-based solutions that require uploading your files to third-party servers, our converter processes everything locally in your browser using JavaScript. Simply upload your file, choose your output format, and download the structured JSON data.

How Does Excel to JSON Conversion Work?

Our converter reads your Excel or CSV file directly in the browser using the SheetJS library. It parses the spreadsheet data, applies your configuration (format, indentation, empty cell handling, type parsing), and generates clean JSON output. You can choose between flat arrays, object dictionaries with sheet names as keys, or wrapped root objects. Dot-notation headers are automatically expanded into nested objects.

Why Choose Our Excel to JSON Converter?

  • 100% Private — Your files never leave your device. All processing happens locally in your browser using JavaScript.
  • Completely Free — No hidden fees, no watermarks, no file size limits, no signup required.
  • Multi-Sheet Support — Process multiple sheets from a single workbook and combine them into structured JSON.
  • Nested Object Support — Automatically convert dot-notation column headers into deeply nested JSON structures.
  • Smart Type Parsing — Auto-detect numbers, booleans, and dates from string values in your spreadsheet.
  • No Installation Required — Works directly in your web browser on any device.
  • Flexible Output Formats — Choose from arrays, objects, or wrapped root objects to match your exact data requirements.

FAQ

What file formats can I convert to JSON?+
Our tool supports XLS (Excel 97-2003), XLSX (Excel 2007+), and CSV (Comma-Separated Values) files. Simply upload any of these formats and the converter will parse them automatically.
Is this Excel to JSON converter free?+
Yes, completely free! There are no hidden fees, no watermarks, no file size limits, and no signup required. You can convert as many files as you need.
Are my files uploaded to a server?+
No! All processing happens entirely in your browser using JavaScript. Your files never leave your device. This makes it safe for confidential data.
What JSON output formats are available?+
We offer three output formats: Flat Array (rows from the first selected sheet), Object Dictionary (all selected sheets as keys), and Wrapped Root Object (data wrapped in a root 'data' key).
Can I convert multiple sheets at once?+
Yes! When you upload an Excel file with multiple sheets, you can select which sheets to include. Use the Object Dictionary or Wrapped Root format to include data from all selected sheets.
What does dot-notation nesting mean?+
If your spreadsheet has column headers like 'address.city' or 'user.name.first', the converter can automatically expand them into nested JSON objects like { address: { city: ... } }. You can toggle this feature on or off.
How are empty cells handled?+
You have three options: Omit the key entirely from the JSON output, set the value to null, or set it to an empty string. Choose the option that best fits your data processing needs.
Can I minify the JSON output?+
Yes! Choose the indentation setting: 2 spaces (standard), 4 spaces, or minified (no spaces) for the most compact output. Minified JSON is ideal for API payloads and production use.