Excel to JSON Converter Online (Free) - XLSX to JSON

When spreadsheet data needs to feed an API, a web app or a test fixture, JSON is the format you want - structured, typed and ready for code. This guide explains how a sheet maps to a JSON array and shows how to convert workbooks with the free Excel to JSON Converter. It keys each row by your header row, supports .xlsx, .xls and .ods, and runs entirely in your browser so your data is never uploaded.

How a spreadsheet maps to JSON

A spreadsheet sheet is a grid. The first row usually holds column headers, and each row below is a record. JSON represents the same thing as an array of objects, where each object is a row and each header becomes a key.

The converter reads the header row to get field names, then walks each data row, pairing every cell value with its column name to build an object. Formula cells contribute their calculated values, since that is the data you actually want. The result is a clean JSON array you can paste straight into code.

Because a workbook can hold several sheets, each sheet maps to its own JSON array. You pick the sheet you want and the converter produces the corresponding objects.

How to use the Excel to JSON Converter

The flow is short:

1. Open the Excel to JSON Converter.
2. Drop in or select your .xlsx, .xls or .ods file.
3. Choose the sheet to convert if there is more than one.
4. The tool reads the header and builds a JSON array of objects.
5. Copy the JSON or download it as a .json file.

No account, no install. Conversion is instant and local, so you can convert internal data without it leaving your machine.

Example: sheet to JSON array

A sheet like this:

becomes a JSON array of two objects. The first is name Jane, age 30, city Paris; the second is name Omar, age 25, city Cairo. Each header cell turned into a key, and each data row turned into one object, ready to use in JavaScript, a config file or an API mock.

Use cases

Excel to JSON conversion fits many developer tasks:

• Seeding: turn a spreadsheet into JSON fixtures for tests or a database import.
• API mocking: generate a realistic JSON response from sample rows.
• Front-end data: load spreadsheet-sourced content into a JavaScript app.
• Config: convert a sheet of settings into a structured config file.
• Migration: move tabular data into a system that ingests JSON.

If you need a plain grid instead, the Excel to CSV converter outputs CSV, and the reverse trip from a CSV is handled by the CSV to JSON tool.

Tips and common mistakes

A few pointers:

• Keep a clean header row. The first row supplies the keys, so make sure it has clear, unique names and no blank cells.
• Pick the right sheet. In a multi-sheet workbook, double-check you converted the sheet you actually need.
• Types: numbers and dates may come through as strings depending on cell formatting. Cast or parse them in code if you need true types.
• Empty cells: missing values usually appear as empty strings or are omitted, which is expected.
• Merged cells and headers spanning columns can confuse the mapping; unmerge them in the source for a clean result.

Privacy: in-browser conversion

Spreadsheets routinely hold sensitive business or personal data. The Excel to JSON Converter reads and converts your file entirely in your browser with JavaScript, so it is never uploaded, logged or stored on a server. The data never leaves your device.

That makes it safe for confidential workbooks. Browse more private data tools in the dev tools category or see all tools.