How to Convert an Excel File with Multiple Sheets to JSON

Excel workbooks often contain multiple sheets — one per month, one per region, one per data category. Converting a multi-sheet workbook to JSON requires a decision: do you need one sheet at a time, or all sheets combined into a single structure? This guide covers both approaches.

How the Sheet Selector Works in the Browser Converter

When you upload an Excel workbook with multiple sheets, the browser-based converter displays a sheet selector dropdown. Each sheet in the workbook appears as an option.

Steps:

1. Upload your .xlsx file to the converter
2. A dropdown appears listing all sheet names in the workbook
3. Select the sheet you want to convert
4. The JSON output updates immediately for that sheet
5. To convert another sheet, select it from the dropdown — the output updates again

This approach is fast for converting one or two specific sheets. You can download the JSON for each sheet separately and name the files accordingly.

Converting Each Sheet to a Separate JSON File

For workbooks with several sheets, convert and download each sheet one at a time:

1. Upload the workbook
2. Select Sheet 1 from the dropdown
3. Click Download JSON — rename the file to sheet1.json or a descriptive name
4. Select Sheet 2 from the dropdown
5. Download again — rename to sheet2.json
6. Repeat for each sheet

You now have one JSON file per sheet. Each file contains a flat array of objects, where row 1 column headers become the JSON property names.

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Combining All Sheets Into a Single JSON Structure

If you need all sheets in a single JSON file, the browser-based converter does not do this automatically — it converts one sheet at a time. To combine them, merge the separate JSON files after downloading.

Simple approach (text editor): Download each sheet as JSON, then manually combine them into a JSON object:

{
  "January": [ ...sheet1 data... ],
  "February": [ ...sheet2 data... ],
  "March": [ ...sheet3 data... ]
}

Automated approach (Python):

import json

sheets = {}
for name in ["January", "February", "March"]:
    with open(f"{name}.json") as f:
        sheets[name] = json.load(f)

with open("combined.json", "w") as f:
    json.dump(sheets, f, indent=2)

For one-off conversions, the manual text editor approach takes about 2 minutes per workbook.

Best Practices for Naming Multi-Sheet JSON Files

When converting multiple sheets, consistent naming prevents confusion:

• Use the sheet name as the filename: Sales_Q1.json, Sales_Q2.json
• Avoid spaces in filenames — use underscores or hyphens
• If combining into one object, use the sheet name as the top-level key
• Keep sheet names in Excel short and descriptive before converting — they become your JSON keys

When Python Is a Better Fit Than the Browser Tool

The browser converter handles most multi-sheet use cases well. Consider Python when:

• You have 10+ sheets and need all of them combined automatically
• You need to process the same workbook repeatedly (schedule, automation)
• You need transformations beyond simple row-to-object conversion

The openpyxl library reads all sheets in a loop: for sheet_name in wb.sheetnames. For one-off work, the browser tool is faster. For repeating tasks, Python is the better investment.

See our guide: Excel to JSON: Python vs browser tools compared.

Frequently Asked Questions

Can I convert all sheets in an Excel workbook to JSON at once?

The browser-based converter handles one sheet at a time via a dropdown selector. To combine all sheets into one JSON file, download each sheet separately and merge the files manually or with a short Python script.

How do I select which sheet to convert in the Excel to JSON tool?

When you upload a multi-sheet workbook, a dropdown appears listing all sheet names. Select the sheet you want, and the JSON output updates immediately. Download each sheet separately as needed.

What happens to hidden sheets when converting Excel to JSON?

The converter lists all sheets in the workbook, including hidden ones. Hidden sheets appear in the dropdown alongside visible ones. You can convert them the same way.

How do I convert an Excel tab to JSON?

Each tab in an Excel workbook is a sheet. Upload the workbook to the browser converter, select the tab (sheet) from the dropdown, and click Download JSON. Each tab produces a separate JSON array.