CSV to JSON Converter - Turn Spreadsheets into JSON Online (Free)

Turn Any CSV Into a JSON Array in Seconds

Paste your CSV data above and get a clean JSON array of objects instantly. Every column header becomes a key, every row becomes an object — no signup, no upload, nothing sent to a server.

How to Convert CSV to JSON

1. Paste your CSV into the input box (or upload a .csv file).
2. Pick your delimiter — comma, semicolon, tab, or pipe. The tool auto-detects in most cases.
3. Click Convert and your JSON appears instantly in the output panel.
4. Copy or download the result with one click.

Worked Example: CSV to JSON

Say you have a small CSV export from a spreadsheet or database:

name,age,city
Alice,30,New York
Bob,25,London

Paste that in and the converter produces this JSON array:

[
  { "name": "Alice", "age": "30", "city": "New York" },
  { "name": "Bob", "age": "25", "city": "London" }
]

Each header row column maps to a key, and each data row maps to one object. Quoted fields with embedded commas or line breaks are handled correctly — for example, "Smith, John" stays as one value, not split at the comma.

Quick Snippet-Bait: What the Conversion Looks Like

Here is the exact mapping at a glance:

Your data never leaves your browser. The conversion runs entirely in client-side JavaScript — nothing is uploaded to any server.

How to Do This in Python and JavaScript

Need to automate the same conversion in your own code? Here are the most common one-liners.

Python

import csv, json

with open('data.csv', newline='', encoding='utf-8') as f:
    rows = list(csv.DictReader(f))

print(json.dumps(rows, indent=2))

csv.DictReader uses the first row as keys automatically. The result is a list of dictionaries — identical to the JSON array this tool produces.

JavaScript (Node.js, using the built-in fs module)

const fs = require('fs');

const text = fs.readFileSync('data.csv', 'utf8');
const [headerLine, ...dataLines] = text.trim().split('\n');
const headers = headerLine.split(',');

const json = dataLines.map(line => {
  const values = line.split(',');
  return Object.fromEntries(headers.map((h, i) => [h.trim(), values[i]?.trim()]));
});

console.log(JSON.stringify(json, null, 2));

This minimal snippet works for simple CSVs. For files with quoted fields or embedded commas, use a library like Papa Parse — it handles edge cases the same way this tool does.

How It Works Under the Hood

The converter parses your CSV according to RFC 4180, the widely-followed specification for comma-separated values. It reads the first row as field names (the JSON keys), then walks each subsequent row, pairing each value with its matching header.

Quoted fields — anything wrapped in double quotes — are treated as a single value even if they contain commas, newlines, or quote characters. The output is a JSON array of objects, the format expected by most REST APIs, JavaScript frontends, and data-processing tools.

Type coercion (turning "30" into the number 30) is optional and off by default, so your data comes out exactly as it appears in the CSV.

When to Use This Tool (and When Not To)

Good fits

• Converting a spreadsheet export to feed a web API or JavaScript app.
• Quickly previewing what a CSV looks like as structured data.
• One-off conversions where writing a script would be overkill.
• Transforming tab-separated or pipe-delimited exports from databases or BI tools.

Think twice if…

• Your file is very large (hundreds of MB). Browser memory has limits; for giant files a server-side script or command-line tool is faster.
• You need nested JSON. CSV is flat by nature — it cannot represent arrays-within-objects or multi-level nesting. You would need to transform the flat output afterward.
• You want to go the other way. If you need to turn JSON back into a spreadsheet-friendly format, the JSON to CSV Converter handles that in one step.

Bottom line: if you have a CSV and need JSON right now, paste it in above and you are done in seconds.