JSON Excel Tool

Documentation

Learn how to use the JSON ↔ Excel converter effectively

Getting Started
Troubleshooting
Advanced Features
Excel Integration

Quick Start Guide

Converting JSON to Excel

  1. Navigate to the JSON → Excel page
  2. Upload your JSON file, paste JSON text, or fetch from a URL
  3. Configure flattening options and array handling strategy
  4. Preview the converted data in the table view
  5. Download as XLSX or CSV

Converting Excel to JSON

  1. Navigate to the Excel → JSON page
  2. Upload your XLSX, XLS, or CSV file
  3. Select the sheet and header row
  4. Configure type inference and empty cell policies
  5. Preview and download the JSON output

Fix "Extra Characters at End of JSON Input"

Common Causes

  • NDJSON Format: Your file contains line-delimited JSON (one JSON object per line)
  • Multiple Objects: Multiple JSON objects without array wrapping
  • Trailing Commas: Extra commas at the end of arrays or objects

Solutions

Enable NDJSON Detection

Turn on NDJSON detection in the options panel. The tool will automatically detect and merge line-delimited JSON into an array.

Wrap in Array

If you have multiple objects, wrap them in square brackets: [{...}, {...}]

Long Numbers in Excel

The Problem

Excel converts large numbers (like IDs or phone numbers) to scientific notation, losing precision. For example, 1234567890123456 becomes 1.23457E+15.

Solution

Enable Long Number Guard

Turn on the "Long Number Guard" option in the conversion settings. This forces Excel to treat large numbers as text, preserving all digits.

// Numbers longer than 15 digits are stored as text
1234567890123456 → "1234567890123456"

Understanding Flattening

What is Flattening?

Flattening converts nested JSON objects into flat column names using a separator (default: dot).

Example

Input JSON:

{
  "customer": {
    "name": "John",
    "address": {
      "city": "NYC"
    }
  }
}

Flattened Columns:

customer.name → "John"
customer.address.city → "NYC"

Custom Separator

You can change the separator from "." to "_" or any other character in the options panel.

Using Power Query in Excel

Import JSON Directly

Excel's Power Query can import JSON files directly. Here's how:

  1. Go to Data → Get Data → From File → From JSON
  2. Select your JSON file
  3. Power Query Editor will open with your data
  4. Click "To Table" to convert to a table format
  5. Expand nested columns using the expand button
  6. Click "Close & Load" to import into Excel

When to Use This Tool Instead

  • You need more control over flattening and array handling
  • You want to preserve long numbers and leading zeros
  • You need to process multiple files in batch
  • You want to save mapping templates for reuse