🔄 JSON to CSV / CSV to JSON Converter
Convert between JSON and CSV formats with nested object flattening, custom delimiters, and flexible options.
Last updated: May 18, 2026 · By Λ
Free JSON to CSV / CSV to JSON Converter
Convert JSON arrays of objects to CSV with automatic header extraction, or parse CSV files back into structured JSON. Nested JSON objects are flattened using dot notation (e.g., "address.city"). Supports custom delimiters including comma, semicolon, tab, and pipe. Handles edge cases like quoted fields containing commas, newlines within values, and escaped quotes. The conversion logic is plain JavaScript bundled into this page, so the records you paste stay inside the tab instead of passing through a server.
What is a JSON to CSV Converter?
A JSON to CSV converter transforms structured JSON data into comma-separated values (CSV), a flat tabular format widely used in spreadsheets, databases, and data analysis tools. JSON (JavaScript Object Notation) organizes data as nested key-value pairs and arrays, while CSV represents data as rows and columns separated by a delimiter. Converting between these two formats is a routine task for developers, data analysts, and anyone who works with APIs or datasets that output JSON but need to be imported into Excel, Google Sheets, or a relational database.
This free online tool handles both directions: JSON to CSV and CSV to JSON. It runs entirely in your browser, so your data is never uploaded to a server. Unlike desktop software or command-line scripts, there is nothing to install and no account to create. Simply paste your data, choose your options, and get instant results. The converter automatically flattens nested objects using dot notation, handles quoted fields that contain commas or newlines, and supports custom delimiters including comma, semicolon, tab, and pipe characters.
How to Use This Tool
- Select the conversion direction using the tabs at the top: JSON to CSV or CSV to JSON.
- Choose your preferred delimiter (comma, semicolon, tab, or pipe) and toggle options like "Include headers" or "Quote all fields."
- Paste or type your JSON array (or CSV text) into the input area. The tool also auto-converts when you paste.
- Click the Convert button to generate the output. Use Copy Output to send the result to your clipboard, or Download to save it as a .csv or .json file.
Key Features
- Nested Object Flattening - Automatically converts nested JSON objects into flat CSV columns using dot notation (for example, address.city becomes a column header).
- Custom Delimiters - Choose from comma, semicolon, tab, or pipe to match the requirements of your target application or regional conventions.
- Bidirectional Conversion - Convert JSON to CSV or CSV back to JSON with a single click, including automatic type detection for numbers, booleans, and null values.
- Quoted Field Handling - Properly escapes fields containing delimiters, newlines, or double quotes, following RFC 4180 CSV conventions.
- Instant Download - Save your converted output directly as a .csv or .json file without any extra steps.
Frequently Asked Questions
What happens to nested JSON objects during conversion?
Nested objects are flattened using dot notation. For example, a JSON field like {"address": {"city": "NYC"}} becomes a CSV column named "address.city" with the value "NYC". Arrays within objects are serialized as JSON strings in the CSV output. When converting back from CSV to JSON, dot-notation headers are automatically unflattened into nested objects.
Is my data safe when using this converter?
Yes. Parsing and serialization both execute as local script in the open tab, and nothing you enter is transmitted, logged, or retained. Loading the page, going offline, and converting again is a quick way to prove that to yourself.
Can I convert a single JSON object instead of an array?
Yes. If you paste a single JSON object (not wrapped in an array), the tool automatically wraps it in an array and produces a CSV with one data row plus a header row. This makes it easy to convert individual records without modifying your input.
Why would I use a semicolon or tab delimiter instead of a comma?
Some regions use commas as decimal separators in numbers, so semicolons are the standard CSV delimiter in many European countries. Tab-separated values (TSV) are useful when your data contains many commas, since tabs rarely appear in regular text. Pipe delimiters are common in legacy systems and mainframe data exports.