BrowserTools

CSV to JSON Converter

Spreadsheet rows to clean JSON objects

By Guga — BrowserTools maintainer, Tbilisi, Georgia Updated 2026-09-16
Free Private No uploads
What is CSV to JSON Converter?

The parser here is properly quote-aware rather than a naive split on commas, so a field like "Doe, Jane" or a value containing a doubled quote survives intact, and CRLF line endings from a Windows export are handled. The first row is taken as the header and every later row becomes an object keyed by those names. The part worth thinking about is type detection. Empty cells become null, the exact words true and false become booleans, and anything that parses as a number becomes one — which is convenient for analysis and quietly destructive for identifiers. A postcode written 01234 arrives as 1234, and a telephone number beginning with a plus arrives without it. A semicolon-delimited file is not split, because the parser treats the comma as the only separator.

Paste CSV data and get a typed JSON array — automatic number and boolean detection, header mapping and quote-aware parsing included. The quick bridge between spreadsheets and code.

Private CSV to JSON Converter In Your Browser

CSV to JSON Converter is processed locally with client-side JavaScript. Your files never touch a server, and there is no queue to wait in.

Step-by-Step

How to use CSV to JSON Converter

1

Choose the CSV → JSON tab and paste your delimited text into the input box.

2

Confirm the first row is the header, since its values become the object keys.

3

Read the two-space-indented JSON array in the output panel.

4

Inspect any values that lost leading zeros or a leading plus, and wrap them in quotes in the source if that matters.

Key Capabilities
  • Quote-aware parsing with doubled-quote escapes and commas inside fields
  • Type detection for numbers, the literals true and false, and null for empty cells
  • Header row mapped onto object keys, with short rows padded and long rows truncated to the header
  • CRLF and LF line endings both accepted, with fully blank rows discarded
Common Use Cases
  • A developer loading an exported customer list into code as an array of objects.
  • A data analyst converting a spreadsheet range into JSON for a quick inspection in a console.
  • A tester checking how a hand-written CSV fixture parses before wiring it into a test.
Clear Answers

Frequently Asked Questions

Why did my postcode lose its leading zero?
Because type detection read it as a number. Anything that converts cleanly through a numeric parse becomes one, so 01234 arrives as 1234 and a telephone number beginning with a plus loses the sign. The cleanest fix is to quote the value in the source file, which forces it to stay a string.
Will it read a semicolon-separated file?
No. The parser treats the comma as the only field separator, so a European export using semicolons comes back as one long column per row. Convert the file to comma-separated first — quoting the fields makes that a safe operation even where values contain commas.
Which words become booleans?
Only the lower-case literals true and false, matched exactly. TRUE, True and FALSE all stay strings, as does yes and no, because the parser is not guessing at intent. That inconsistency is worth knowing if your source is inconsistent.
What if a cell contains the word Infinity?
It is recognised as a number when the value is cast, and JSON has no way to write an infinite number, so the field is emitted as null. Nonnumeric placeholders such as N/A pass through unchanged as text, because they are not valid numbers.