Does this handle quoted fields with commas or newlines inside them?

Yes, the parser follows RFC 4180 quoting rules: a field wrapped in double quotes can contain commas, newlines, and escaped "" sequences without breaking the row structure.

What if a row has fewer columns than the header?

Missing trailing columns are filled in as empty strings, so every object in the output array has the same set of keys.

What if the header row has a blank or duplicate column name?

A blank header cell is replaced with a generic name like column_3 based on its position, so no key is ever lost or silently dropped.

Are values type-converted, e.g. does '3' become the number 3?

No, every CSV cell becomes a JSON string, since CSV itself has no type system. Convert types afterward in your own code if you need numbers or booleans.

CSV to JSON Converter - Convert Online

Overview

Introduction

Spreadsheet exports and database dumps commonly land as CSV, but most application code and APIs expect JSON. This tool converts CSV rows into a JSON array of objects without needing a spreadsheet program or script.

It handles the trickier parts of CSV, quoted fields containing commas or embedded newlines, correctly, so you don't lose data on edge-case rows.

What Is CSV to JSON Converter?

A CSV-to-JSON converter that treats the first row as column headers and every subsequent row as a record, producing a JSON array where each element is an object keyed by those headers.

It implements RFC 4180's quoting rules directly, rather than a naive comma-split, so quoted fields with embedded delimiters parse correctly.

How CSV to JSON Converter Works

The parser scans the input character by character, tracking whether it's inside a quoted field. Only unquoted commas and newlines are treated as delimiters; quoted delimiters and doubled "" sequences are preserved as literal characters.

Once rows of raw cells are extracted, the first row becomes the set of object keys, and each following row is zipped against those keys to build one JSON object per row.

When To Use CSV to JSON Converter

Use it when you've exported data from a spreadsheet or database and need it as JSON for a script, API request, or test fixture.

It's also useful for quickly inspecting whether a CSV export has the columns and row count you expect.

Often used alongside JSON to CSV Converter, TSV to JSON Converter and XML to JSON Converter.

Features

Advantages

Correctly handles RFC 4180 quoting, including commas and newlines inside quoted fields.
Produces a clean, uniform JSON array where every object shares the same keys.
Runs entirely client-side, so exported data never leaves your browser.

Limitations

All values become strings; there's no automatic type inference for numbers, booleans, or dates.
Assumes a single header row; CSV files with multi-row headers need manual adjustment first.

Examples

Converting a small CSV

Input

id,name,active
1,Ada Lovelace,true
2,Alan Turing,false

Output

[
  {
    "id": "1",
    "name": "Ada Lovelace",
    "active": "true"
  },
  {
    "id": "2",
    "name": "Alan Turing",
    "active": "false"
  }
]

Each data row becomes one object, keyed by the header row's column names; every value stays a string.

Best Practices & Notes

Best Practices

If you need typed values (numbers, booleans), convert them in code after this step rather than guessing types from strings.
Check for a blank or duplicate header cell before converting, since those get auto-named as column_N.
Use TSV to JSON instead if your source data is tab-delimited rather than comma-delimited.

Developer Notes

The delimited parser is a single-pass state machine tracking an `inQuotes` flag, rather than a regex split, which is the only reliable way to handle RFC 4180's quoting correctly: a naive input.split(",") would incorrectly break apart any quoted field that itself contains a comma.

CSV to JSON Converter Use Cases

Converting a spreadsheet export into a JSON array for a script or test fixture
Preparing CSV data for a JSON-only API request body
Quickly inspecting the row count and structure of a CSV export

Common Mistakes

Expecting numeric or boolean CSV values to convert to their JSON equivalents automatically; everything stays a string.
Assuming a CSV with a multi-row or merged-cell header will parse cleanly; only a single simple header row is supported.
Forgetting that a trailing blank line in the CSV can produce an extra, mostly-empty object.

Tips

If a column looks wrong, check the CSV for embedded commas that weren't properly quoted at the source.
Pair with JSON to CSV to verify a round trip preserves your data as expected.

CSV to JSON Converter