Utiltown

CSV to JSON Converter

Convert CSV to JSON and JSON back to CSV in your browser. Paste tabular data, choose your separator and whether the first row is a header, and get clean JSON objects or a JSON array — or go the other way and flatten JSON into a CSV table. Fully local: your data never leaves your device.

All computations run locally in your browser, no data uploaded to server. 
  
  
 
How To Use
 
     
  1. Choose the conversion direction: CSV → JSON or JSON → CSV.
    2.  
  2. Pick the separator that matches your data: comma (,), semicolon (;), or tab.
    3.  
  3. For CSV input, tick First row is header to use the first row as object keys. Untick it to get a 2-D array instead.
    4.  
  4. Paste your CSV or JSON into the input box.
    5.  
  5. Click Convert to see the result, or Demo to try a sample.
    6.  
  6. Click Copy to put the converted output on your clipboard.
    7.  
 
 
 
Usage Example
 
Converting the following CSV with header on:
 
name,age
Alice,30
Bob,25
 
produces an array of objects with typed values:
 
[
  {
    "name": "Alice",
    "age": 30
  },
  {
    "name": "Bob",
    "age": 25
  }
]
 

Note that age is emitted as the number 30, not the
        string "30". The converter automatically detects numbers,
        booleans, and JSON-parseable values. Fields that contain a separator,
        such as "red, blue", are double-quoted so they stay in a
        single column.

 
 
 
Frequently Asked Questions
  
How are quoted fields handled?
 
CSV fields wrapped in double quotes, such as "red, blue", are parsed as a single cell even though they contain the separator. Embedded quotes are supported using the standard double-quote escape, and quoted values with newlines are preserved as well.
  
What does the header row do?
 
When First row is header is enabled, the first row of your CSV becomes the keys of the resulting JSON objects. Turning it off returns a plain 2-D array where every row, including the first, is a list of values.
  
Does CSV → JSON return objects or arrays?
 
By default it returns an array of objects keyed by your header row. If you disable the header option, it returns a 2-D array of rows instead. In both cases the result is a valid JSON array.
  
What happens to nested JSON when converting JSON to CSV?
 
Nested objects and arrays in a JSON value are serialized to a JSON string inside a single quoted cell. Values that contain a separator, quote, or newline are wrapped in double quotes so the output stays valid CSV. Nothing is deep-flattened or lost.
  
Is this tool local?
 
Yes. All conversion runs entirely in your browser with no network calls. Your input and output never leave this page.