Excel to JSON Converter

1. How to Use the Excel to JSON Converter

Converting Microsoft Excel spreadsheets (.xlsx, .xls) to JavaScript Object Notation (JSON) transforms tabular workbook data into structured arrays or multi-sheet object maps ready for web APIs and NoSQL databases. Follow these 3 simple steps:

2. What Is Excel to JSON Conversion?

Excel workbooks store tabular grid data organized into rows, columns, formulas, and multiple worksheet tabs. While Excel is the business standard for financial modeling and reporting, software applications, backend services, and NoSQL databases (like MongoDB, Firebase, and PostgreSQL JSONB) exchange data using JSON (JavaScript Object Notation).

Excel to JSON conversion parses the underlying spreadsheet cell grid, maps column header names from row 1 to JSON property keys, converts cell data types into native JSON primitives (numbers, booleans, strings, nulls), and wraps records into clean JSON objects.

3. Convert Excel Rows into JSON Objects

When converting an Excel worksheet grid, Row 1 is automatically extracted as property header keys, and subsequent data rows become typed JSON objects in an array:

[Row 1 Headers]: ID  | Name        | Department  | Active | Salary
[Row 2 Data]   : 101 | Alice Smith | Engineering | TRUE   | 135000
[Row 3 Data]   : 102 | Bob Jones   | Design      | FALSE  | 115000

[
  {
    "ID": 101,
    "Name": "Alice Smith",
    "Department": "Engineering",
    "Active": true,
    "Salary": 135000
  },
  {
    "ID": 102,
    "Name": "Bob Jones",
    "Department": "Design",
    "Active": false,
    "Salary": 115000
  }
]

4. Excel Cell Formats to JSON Data Types

How spreadsheet cell types and formatting rules are mapped into JSON primitives:

5. Date & Serial Number Engine Explained

Excel does not store dates as ISO strings. Instead, dates are stored as floating-point serial numbers representing elapsed days since December 31, 1899 (for example, serial 45123.5 corresponds to 2023-07-15 12:00:00).

ToolMono's conversion engine accounts for Excel date formatting metadata and epoch offsets, outputting clean formatted date strings or ISO timestamps while allowing raw numeric serial extraction when Raw Values is toggled.

6. Multi-Worksheet Conversion Strategy

Workbooks with multiple worksheet tabs can be exported in two distinct structural configurations:

[
  { "ID": 101, "Name": "Alice" },
  { "ID": 102, "Name": "Bob" }
]

{
  "Employees": [{ "ID": 101, "Name": "Alice" }],
  "Inventory": [{ "SKU": "PROD-1", "Stock": 45 }]
}

7. Supported Excel Formats (.xlsx, .xls, .xlsm)

The converter supports all major spreadsheet file specifications:

8. Formulas, Empty Cells & Merged Ranges

Key considerations for complex spreadsheet cell structures:

9. Excel vs JSON Comparison Matrix

10. Practical Conversion Examples

Explore realistic real-world Excel to JSON transformation patterns across diverse business domains:

SKU      | Title                | Price   | Stock | InStock
PROD-001 | Mechanical Keyboard  | 149.99  | 42    | TRUE
PROD-002 | 4K Gaming Monitor    | 499.50  | 0     | FALSE

[
  {
    "SKU": "PROD-001",
    "Title": "Mechanical Keyboard",
    "Price": 149.99,
    "Stock": 42,
    "InStock": true
  },
  {
    "SKU": "PROD-002",
    "Title": "4K Gaming Monitor",
    "Price": 499.50,
    "Stock": 0,
    "InStock": false
  }
]

[Sheet: Employees]
EmpID | Name        | Role
101   | Alice Smith | Engineer

[Sheet: Department_Budget]
Dept        | Q1_Budget | Approved
Engineering | 500000    | TRUE

{
  "Employees": [
    { "EmpID": 101, "Name": "Alice Smith", "Role": "Engineer" }
  ],
  "Department_Budget": [
    { "Dept": "Engineering", "Q1_Budget": 500000, "Approved": true }
  ]
}

Item    | UnitPrice | Qty | TotalPrice (=B2*C2)
Monitor | 250.00    | 4   | [Cached: 1000.00]

[
  {
    "Item": "Monitor",
    "UnitPrice": 250.00,
    "Qty": 4,
    "TotalPrice": 1000.00
  }
]

11. Developer Code Implementation Guide (Python & JS)

Production-grade code implementation snippets for parsing Excel files into JSON across major programming languages:

import pandas as pd

# Load specific sheet from Excel file into DataFrame
df = pd.read_excel("sales_report.xlsx", sheet_name="Q1_Sales")

# Export to JSON array of objects with 2-space indentation
json_data = df.to_json(orient="records", indent=2)

with open("output.json", "w", encoding="utf-8") as f:
    f.write(json_data)

import json
import openpyxl

wb = openpyxl.load_workbook("data.xlsx", data_only=True)
sheet = wb.active

headers = [cell.value for cell in sheet[1]]
records = []

for row in sheet.iter_rows(min_row=2, values_only=True):
    row_dict = {headers[i]: row[i] for i in range(len(headers))}
    records.append(row_dict)

json_output = json.dumps(records, indent=2, default=str)
print(json_output)

const XLSX = require("@e965/xlsx");
const fs = require("fs");

// Read workbook buffer from disk
const workbook = XLSX.readFile("inventory.xlsx");

// Get first worksheet tab
const firstSheetName = workbook.SheetNames[0];
const worksheet = workbook.Sheets[firstSheetName];

// Parse worksheet grid to JSON objects array
const jsonData = XLSX.utils.sheet_to_json(worksheet, {
  raw: true,
  defval: null
});

fs.writeFileSync("inventory.json", JSON.stringify(jsonData, null, 2), "utf8");

package main

import (
	"encoding/json"
	"fmt"
	"github.com/xuri/excelize/v2"
)

func main() {
	f, err := excelize.OpenFile("users.xlsx")
	if err != nil {
		panic(err)
	}
	defer f.Close()

	rows, err := f.GetRows("Sheet1")
	if err != nil || len(rows) < 2 {
		return
	}

	headers := rows[0]
	var result []map[string]string

	for _, row := range rows[1:] {
		item := make(map[string]string)
		for i, colCell := range row {
			if i < len(headers) {
				item[headers[i]] = colCell
			}
		}
		result = append(result, item)
	}

	jsonBytes, _ := json.MarshalIndent(result, "", "  ")
	fmt.Println(string(jsonBytes))
}

12. Methodology & Client-Side Privacy Commit

ToolMono is committed to data privacy and security. Our Excel to JSON Converter parses, validates, and transforms spreadsheet files 100% locally within your browser V8 engine.

Your input Excel workbooks, uploaded files, and generated JSON outputs are never transmitted across the network, stored in remote databases, or logged on servers. This architecture makes ToolMono completely safe for sensitive financial spreadsheets, confidential customer records, and internal enterprise data.

13. Frequently Asked Questions

14. References & Official Standards

Official specifications and standards referenced by ToolMono: