What delimiters does this tool support?

The tool auto-detects commas, semicolons, tabs, and pipes. You can also manually select a delimiter if auto-detection picks the wrong one.

Can I convert JSON back to CSV?

Yes. Switch to JSON → CSV mode, paste an array of objects, and the tool will generate a CSV file with headers derived from the object keys.

Is there a file size limit?

There is no hard limit, but very large files (100MB+) may slow your browser since processing happens client-side. For most use cases (up to ~50MB) it works instantly.

CSV ⇄ JSON Converter

Convert between CSV and JSON in seconds. JSONL support, nested object flattening, Data Inspector with column analysis. 100% client-side — your data never leaves your browser.

📄 CSV Input

📁

Drop a .csv file here

or click to browse — supports .csv, .tsv, .txt

Paste CSV data

Delimiter

Output Format

JSON Indent

‎

First row is header Trim whitespace

🔷 JSON Output

Rows

—

Columns

—

Delimiter

—

File Size

—

🔷 JSON Input

Paste JSON (array of objects or JSONL)

CSV Delimiter

Empty Values

Flatten nested objects (dot notation: address.city)

📄 CSV Output

Rows

—

Columns

—

🔍

No data to inspect yet

Run a conversion on the CSV → JSON or JSON → CSV tab first, then come back here to analyze your data.

Your data stays private. All conversion happens in your browser. Nothing is uploaded to any server.

How to Use This Tool

Add Your Data

Drop a .csv or .json file, or paste text directly. Hit Try Sample for a quick demo with real employee data.

Configure Options

Choose delimiter, output format (Objects / Arrays / JSONL / Keyed), indent style, and whether to flatten nested objects or trim whitespace.

Download, Copy, or Inspect

Download as .json, .jsonl, or .csv, copy to clipboard, or switch to Data Inspector for a full column-level analysis and fill-rate chart.

Frequently Asked Questions

Is my data safe with this converter?

Absolutely. All conversion happens entirely in your browser using JavaScript. Your data never leaves your device — nothing is sent to any server. You can even use this tool offline after the page loads.

What output formats are supported for CSV → JSON?

Four formats: Array of Objects (standard, with column headers as keys), Array of Arrays (raw rows), JSONL (one JSON object per line, newline-delimited), and Keyed Object (first column becomes the dictionary key). You can also choose between Minify, 2-space, or 4-space indentation.

Does the JSON → CSV converter handle nested objects?

Yes. Enable the Flatten nested objects option and nested keys like { "address": { "city": "Austin" } } become a flat column named address.city. This makes deeply nested JSON much easier to work with in spreadsheet tools.

Does it support JSONL or NDJSON?

Yes. The JSON → CSV tab automatically detects JSONL (newline-delimited JSON) where each line is a separate JSON object. It parses them all and converts to CSV without any extra configuration.

What is the Data Inspector tab?

After any conversion, the Data Inspector shows a column-level breakdown: inferred data type (number, string, boolean, mixed), non-null count, null count, unique value count, and sample values. A fill-rate bar chart helps you spot missing data at a glance. You can also copy the detected schema as JSON.