CSV to JSON

Paste CSV or upload a file to convert it into formatted JSON — and back again. Handles custom delimiters, headers, and data types.

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How to Use the CSV to JSON

Paste your CSV data into the left panel or upload a .csv file. The JSON output appears instantly on the right, formatted with 2-space indentation by default. Use the options row to set your delimiter, toggle headers, choose the output structure (array of objects, array of arrays, or keyed by column), and control type detection. The table preview below shows your parsed data with inferred types so you can verify the conversion before downloading. To convert JSON back to CSV, click the ⇄ toggle at the top.

About This Tool

A bidirectional converter between CSV and JSON formats. CSV (Comma-Separated Values) is the most widely supported data interchange format for spreadsheets, databases, and analytics tools. JSON (JavaScript Object Notation) is the standard format for web APIs, configuration files, and NoSQL databases. This tool’s parser is RFC 4180-compliant — it correctly handles quoted fields containing commas, embedded newlines, and escaped double-quotes. Auto-detect mode identifies the delimiter from the first line, supporting comma, tab, semicolon, and pipe-delimited files. Type inference detects numbers and booleans column-by-column for clean, structured JSON output. Zero external libraries — everything runs in your browser. Related: pretty-print JSON to tidy up the JSON you produced here, test regular expressions live for validating column values, and encode special characters for URLs when piping output into query strings.

Quick Reference Table

Output Structure	Best For
Array of objects	Most common — each row becomes a named object
Array of arrays	Compact — no headers, just nested arrays
Keyed by column	Data analysis — one array per column

Frequently Asked Questions

Why are my numbers being converted to strings?

Type detection checks whether ALL values in a column can be parsed as the same type. If any value in a column is not a valid number — an empty cell, ‘N/A’, or a text value — the entire column stays as strings to prevent data loss. Enable ‘Treat empty as null’ in the options to allow columns with empty cells to still be detected as numbers.

My CSV uses semicolons — how do I handle that?

Set the delimiter to Semicolon (;) in the options. The Auto-detect option will usually detect semicolons automatically if they are more frequent than commas in the first line. Semicolon-delimited CSV is common in European locales where the comma is used as a decimal separator.

Can I convert a multi-sheet Excel file?

This tool converts CSV and JSON text formats. For Excel files (.xlsx), export each sheet from Excel as a separate CSV first (File → Save As → CSV). Excel can only export one sheet at a time as CSV.

What happens with special characters and Unicode?

This tool reads CSV files as UTF-8 text, which supports all Unicode characters including emoji, Chinese, Arabic, and Icelandic. If your CSV was saved in a different encoding, characters outside ASCII may display incorrectly. Re-save your file as UTF-8 before uploading.

How big a CSV file can the CSV to JSON converter handle?

The converter processes CSV entirely in your browser with streaming-friendly parsing, so file size is limited mainly by your browser’s memory. CSVs under 50MB (roughly a million rows of typical business data) convert smoothly on modern devices. Much larger files are possible but may cause the browser tab to stall briefly during parsing.

Created by The Toobits Team · Engineering & Editorial

Toobits is built, tested, and maintained by a small independent engineering team. Every tool is written in TypeScript, runs entirely in the browser, and is reviewed against its source formulas before publication.

Editorial policy · Updated April 2026

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