CSV to JSON Converter

Free No sign-up

Convert CSV files to clean JSON in seconds — auto-detects the delimiter and types numbers automatically.

Runs locally in your browser. Your CSV is not uploaded to a server.

Paste or upload CSV • Auto-detect delimiter • Type numbers automatically

Drop your CSV files here or browse
Supports .csv files up to 50 MB · Multiple files at once

What is a CSV to JSON converter?

CSV is the universal export format for spreadsheets and databases, but most apps, APIs, and scripts expect JSON. This tool turns any CSV into a clean array of JSON objects you can paste straight into code, a config file, or an API request — all processed locally in your browser, with no data sent to a server.

The first row of your CSV becomes the object keys, and every following row becomes one object. The delimiter (comma, semicolon, or tab) is detected automatically, and values that look like numbers, true/false, or null are converted to real JSON types instead of being left as strings. Empty cells become null. If your data lives in a spreadsheet, export it first with our Excel to CSV Converter, then drop the file here.

Header rowFirst row becomes the JSON keys
DelimiterAuto-detected: comma, semicolon, or tab
Type inferenceNumbers, true/false, and null are typed automatically
OutputPretty-printed JSON array, 2-space indent

How to use this tool

File mode. Drop one or more .csv files into the drop zone. Each file appears as a card showing the row count and detected delimiter. Preview the JSON and download the .json file.

Paste mode. Switch to the Paste tab and paste your CSV into the left panel. The JSON output appears instantly on the right. Copy the text or download the file.

Frequently Asked Questions

How are the JSON keys created?
The first row of your CSV is used as the keys. Each following row becomes one JSON object, so a CSV with columns name,email produces objects like {"name":"Sam","email":"[email protected]"}.
Does the tool detect the delimiter automatically?
Yes. It checks the header row for commas, semicolons, and tabs and picks the most likely one. This handles standard CSV, European semicolon-separated files, and tab-separated (TSV) data.
Will numbers stay as text or become real numbers?
Values that look like numbers, true, false, or null are converted to real JSON types. Everything else stays as a string, so IDs with leading zeros and phone numbers are preserved as text.
What happens to empty cells?
Empty cells become null in the JSON output, which is the safest default for downstream code and APIs.
Does my CSV get uploaded to a server?
No. Everything runs in your browser. Your CSV data never leaves your device.