Excel to JSON Converter Online – Free XLS/XLSX to JSON Tool

About Excel to JSON Converter

The Excel to JSON Converter allows you to upload one or multiple Excel files and convert them into structured JSON format. It reads all sheets inside each Excel file, transforms rows into JSON records, and provides a formatted preview with download options.

This tool is designed for users who need to transform spreadsheet data into JSON for development, APIs, data processing, or integration workflows.

What Is This Tool?

This tool converts Excel files (.xlsx and .xls) into properly formatted JSON output.

You can:

• Upload multiple Excel files

• Convert all sheets automatically

• Preview JSON in an interactive viewer

• Copy full JSON content

• Download as JSON, TXT, or ZIP

The conversion is handled server-side using pandas to ensure accurate sheet and row processing.

Supported Excel Formats

The tool supports:

• .xlsx (Excel Open XML format)

• .xls (Legacy Excel format)

Files that are not Excel format are ignored during upload.

Multiple Excel files can be uploaded and processed in a single session.

Output JSON Structure

The JSON structure depends on the number of sheets inside the Excel file.

If the Excel file contains one sheet:

The output will be a JSON array of objects:

[
  { "column1": "value", "column2": "value" },
  { "column1": "value", "column2": "value" }
]

Each row becomes a JSON object using column headers as keys.

If the Excel file contains multiple sheets:

The output will be a JSON object where:

• Keys = sheet names

• Values = array of records for that sheet

Example structure:

{
  "Sheet1": [ {...}, {...} ],
  "Sheet2": [ {...}, {...} ]
}

This ensures that all sheets are preserved in the final JSON output.

Key Features

• Multiple File Upload

• Drag & Drop Support

• All Sheets Conversion

• Structured JSON Records\

• Pretty-Formatted JSON

• JSON Preview Viewer

• Record Count Display

• Sheet Count Display

• File Size Information

• Large File Handling

• Copy Full JSON

• Download Options

How It Works

Step 1: Upload Excel File(s)

Upload .xlsx or .xls files via drag-and-drop or file selector.

Step 2: Temporary Storage

Files are stored securely in a temporary server directory with unique filenames.

Step 3: Sheet Processing

The tool:

• Reads all sheet names

• Loads each sheet into a dataframe

• Converts rows to dictionary records

Step 4: JSON Generation

• If single sheet → returns array

• If multiple sheets → returns object grouped by sheet names

• JSON is formatted with indentation

Step 5: Preview & Download

Converted JSON is displayed in the viewer and can be copied or downloaded.

JSON Viewer & Preview Features

The tool includes a built-in JSON viewer powered by CodeMirror:

• Line numbers

• Code folding (Fold All / Unfold All)

• Bracket matching

• Search inside JSON

• Fullscreen view

• Read-only mode for safety

Keyboard shortcuts are supported for search and folding.

Large File Handling

If the generated JSON exceeds 50,000 characters, the tool:

• Shows only the first 50KB preview

• Displays a large file warning

• Disables search and folding for performance

• Still allows copying the complete JSON

• Allows full download of the complete file

This ensures stable performance even for large Excel datasets.

Download Options

You can download:

Single File:

• As .json

• As .txt (plain text version of JSON)

Multiple Files:

• Download all converted files together as a ZIP archive

Error Handling & Validation

The tool detects and handles:

• Invalid request methods

• Missing files

• Unsupported file types

• Excel parsing errors

• Empty Excel files

• File not found during conversion

If a file fails to convert, an error message is displayed for that specific file.