How to Convert Excel Workbooks (.xlsx / .xls) to JSON Online
Converting tabular spreadsheets into JSON is a routine task when seeding databases, building API payloads, importing product catalogs, and automating data pipelines. TinyTools Excel to JSON Converter provides a client-side conversion engine that transforms Microsoft Excel workbooks directly into JSON arrays with complete control over headers, sheet selection, and indentation.
Step-by-Step Conversion Guide
- Select File: Drag and drop your
.xlsx,.xls, or.csvspreadsheet into the dropzone, or click to browse your local device. - Choose Active Sheet: If your workbook contains multiple tabs, select the desired worksheet from the Active Sheet dropdown.
- Set Header Preferences: Leave First row contains headers checked if your sheet has column titles (e.g. ID, Name, Price). Uncheck it to generate an array of row arrays.
- Export JSON: Click Copy JSON to copy the output to your clipboard, or click Download .json to save the file.
Excel to JSON Conversion Example
Suppose your Excel sheet contains the following rows of product data:
| SKU | Product | Price | Available |
|---|---|---|---|
| PRD-101 | Smart Thermostat | 149.99 | TRUE |
| PRD-102 | Door Sensor | 29.50 | FALSE |
The generated JSON array parses data types cleanly (numbers as floats/integers, booleans as true/false):
[
{
"SKU": "PRD-101",
"Product": "Smart Thermostat",
"Price": 149.99,
"Available": true
},
{
"SKU": "PRD-102",
"Product": "Door Sensor",
"Price": 29.5,
"Available": false
}
]
Common Developer Use Cases
Database Seeding
Convert client-provided spreadsheets into JSON fixtures for MongoDB, PostgreSQL, Firebase, or Prisma seed scripts.
API Mock Data & Testing
Generate realistic JSON arrays for Postman collections, Cypress tests, and frontend development before production APIs are ready.
CMS Content Migration
Migrate legacy Excel spreadsheets containing blog articles, product categories, or translation dictionaries into headless CMS platforms.
Confidential Data Handling
Convert sensitive business spreadsheets containing salary tiers, medical codes, or internal user lists without uploading data to external servers.
Technical Details & SheetJS Engine
This converter is powered by SheetJS, the industry standard for spreadsheet processing. The library reads raw binary byte streams using FileReader.readAsArrayBuffer:
- Formula Evaluation: Formula cells export their evaluated cache values rather than the raw formula string.
- Date Parsing: Excel stores dates internally as floating point numbers representing days since January 1, 1900. SheetJS resolves these into formatted date strings.
- Blank Cell Handling: Completely empty rows are pruned to keep your JSON array clean and concise.