Rows to Objects
Each CSV row becomes a JSON object keyed by your header row — or an array of arrays if you prefer.
DEVELOPER TOOL / CSV TO JSON
Free Online CSV to JSON Converter
Convert CSV data into clean, structured JSON in your browser. Use the first row as keys, detect numbers and booleans automatically, and handle quoted values and different delimiters with ease.
Paste your CSV or open a file. Nothing is uploaded — everything is processed on your device.
✓ Free to use · No signup required · Processed in your browser
CSV to JSON Converter workspace
PASTE CSV · CHOOSE OPTIONS · CONVERT · DOWNLOAD JSON
Paste CSV and click Convert to JSON.
CSV TO JSON WORKSPACEMOSANKIT / DEVELOPER TOOLS
THE BASICS
What Is a CSV to JSON Converter?
CSV (comma-separated values) is the simple table format used by spreadsheets and exports. JSON is the format most web apps and APIs expect. A CSV to JSON converter turns each row into a JSON object, using the header row as the property names.
It saves you writing a throwaway script whenever you need to move spreadsheet data into an app, a test fixture, a config file or an API request.
BUILT FOR THE JOB
Key Features of MoSanKit CSV to JSON Converter
Auto-Detect Delimiter
Comma, semicolon, tab and pipe are detected automatically, or choose one yourself.
Smart Type Detection
Optionally turn numbers, true/false and null into real JSON types. Values like 007 stay as text.
Handles Real-World CSV
Quoted values, escaped quotes, line breaks inside cells and Windows line endings all work.
Pretty or Minified
Choose readable output or compact JSON for production use.
Private by Design
Files are read locally in your browser and never uploaded.
QUICK AND SIMPLE
How to Convert CSV to JSON
01 / ADD
Paste or open your CSV
Paste CSV into the box or choose a file from your device.
02 / OPTIONS
Set your options
Choose the delimiter, header row, type detection and output style.
03 / CONVERT
Click Convert to JSON
The JSON appears instantly with a row count.
04 / EXPORT
Copy or download
Copy the JSON or save it as a .json file.
MADE FOR EVERYDAY WORK
Who Can Use This Tool?
DevelopersCreate JSON fixtures and seed data from spreadsheets.
Data AnalystsPrepare spreadsheet data for apps and visualisation tools.
MarketersMove exported lists into tools that accept JSON.
QA EngineersBuild test data from tables.
StudentsLearn how tabular and structured data relate.
Product TeamsTurn content spreadsheets into data for prototypes.
GOOD TO KNOW
A few things, answered.
Quick answers about using the MoSanKit CSV to JSON Converter.
Yes. It is free with no sign-up and no limits on how often you use it.
Yes. When type detection is on, numbers with leading zeros stay as text so IDs and phone numbers are not changed.
Yes. The delimiter is detected automatically, or you can choose comma, semicolon, tab or pipe.
Turn off "First row is the header" and you will get an array of arrays instead of objects.
Missing values are filled with empty text and extra values are ignored. The tool tells you how many rows were affected.
No. Files are read and converted in your browser, and nothing is sent to a server.
Spreadsheet in,
JSON out.
Explore more free developer tools from MoSanKit.