How do I convert JSON to CSV?

Paste your JSON data into the input box above and click Convert. The tool automatically flattens nested objects and arrays into CSV columns. You can then copy the result or download it as a .csv file.

Can this tool handle nested JSON?

Yes. Nested objects are flattened using dot notation (e.g. 'address.city') and arrays are joined with semicolons by default. This ensures all data is preserved in the CSV output.

What is the maximum JSON size supported?

There is no hard limit. The tool handles files up to several megabytes efficiently. For extremely large datasets, processing time depends on your browser and device.

JSON to CSV Converter Online — Free & Client-Side

JSON Input

Delimiter:

Flatten nested objects

CSV Output

How to Convert JSON to CSV Online

JSON (JavaScript Object Notation) is the preferred format for APIs and web services, but it is notoriously difficult to read or manipulate for non-developers. CSV (Comma-Separated Values) remains the standard for data analysts, marketers, and business operations because it imports directly into spreadsheet software like Microsoft Excel or Google Sheets. This online JSON to CSV converter bridges the gap instantly.

Step-by-Step Conversion Guide

Paste JSON Input: Paste your JSON data (either a single object or an array of objects) into the input box above.
Choose Delimiter: Choose whether to separate columns with Commas (standard CSV), Tabs (TSV), Semicolons, or Pipes.
Flatten Nested Fields: Keep the "Flatten nested objects" box checked if your JSON has nested hierarchies you want converted into flat columns (e.g. user.address.street).
Convert and Save: Click the blue "Convert to CSV" button, then copy the result to your clipboard or download it as a .csv file.

The Flattening Problem: Handling Nested JSON Structures

A standard spreadsheet is a flat two-dimensional table (rows and columns). JSON, however, is hierarchical and can nest objects inside other objects or contain nested lists (arrays). How does conversion handle this structural difference?

Nested Objects: Our tool flattens objects using standard dot notation. For example, if you have {"user": {"profile": {"name": "Alice"}}}, it is converted into a column header named user.profile.name with the cell value Alice.
Nested Arrays: Arrays containing primitive values (like strings or numbers) are joined into a single string separated by semicolons (e.g. ["admin", "billing"] becomes admin;billing in the CSV cell).
Array of Objects: Arrays of complex objects are expanded using index numbering (e.g. items[0].price, items[1].price) to guarantee no data is lost.

Frequently Asked Questions

Why does my CSV look weird in Microsoft Excel?

Microsoft Excel sometimes fails to auto-detect the encoding (UTF-8) or delimiter of a CSV file. If your data contains special characters or uses tab/semicolon separators, import the file into Excel using the Data > From Text/CSV wizard rather than double-clicking the file directly. This allows you to explicitly configure the encoding and delimiter.

What happens if my JSON objects have different keys?

Our converter automatically scans all objects in the input array to collect every unique key. If some objects are missing specific keys, the tool will output empty values (blank cells) for those rows, ensuring your columns line up perfectly.

Is there a file size limit?

Since the conversion runs entirely client-side inside your browser, there is no artificial file size limit. It depends strictly on your device's memory. The converter can easily parse several megabytes of JSON data (tens of thousands of records) in a few seconds.

Is my JSON data kept private?

Yes. Because all parsing and serialization happens inside your local browser runtime, no data ever leaves your device or goes over the internet. There are no server uploads, making it completely safe to convert sensitive business spreadsheets, CRM records, or user databases.

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🔒 100% Client-Side Privacy

All JSON parsing and CSV generation happens entirely in your browser using JavaScript. No data is ever uploaded to any server. Your JSON stays on your device at all times. This tool requires no login, no API key, and no permissions.