CSVCSV Dock

Private, local-first data tools

Convert CSV to JSON

Turn CSV rows into objects, two-dimensional arrays or JSON Lines, with optional type inference and explicit empty-value handling.

Processed in your browserNo account requiredEncoding and delimiter controlsIncomplete exports are blocked
JSON export options
Drop a file, paste data, load a CORS-enabled URL, or try the sample.
Rows0
Columns0
EncodingAuto
DelimiterAuto
Issue groups0

Open a data file to start

The parser runs off the main thread. Once loaded, you can search, sort, validate, repair and export without an account.

What this tool does

Convert CSV to JSON

This page maps each retained CSV row to headers and generates one of three JSON shapes. Safe type inference recognizes booleans, null and numeric values without converting identifiers that start with zero.

How to use it

  1. Open or paste CSV and verify the detected header and delimiter.
  2. Choose objects, a two-dimensional array or newline-delimited JSON.
  3. Control type inference and empty cells, preview the rows and download JSON.

Common tasks

  • Convert CSV to a JSON object array, two-dimensional array or JSON Lines.
  • Preserve leading-zero IDs while safely inferring booleans, nulls and numbers.
  • Repair duplicate headers before using CSV rows as JSON object keys.

Privacy and local processing

Local files are read by a dedicated browser worker and are not uploaded to an application server. File contents and filenames are not included in analytics events. Loading a public URL is an explicit direct request from your browser and may fail when the remote server blocks CORS.

Supported edge cases

  • Values such as 000184 stay strings even when type inference is enabled.
  • Duplicate headers are reported and can be made unique before conversion.
  • JSON Lines writes one object per line and uses the .jsonl extension.

Frequently asked questions

What JSON structure should I choose?

Use objects for most APIs, arrays when positional data is required, and JSON Lines for streaming or data-engineering workflows.

Will IDs be converted to numbers?

Identifiers with leading zeros remain strings. Other unambiguous numeric values can be inferred when the option is enabled.

How are empty CSV cells represented?

They are empty strings by default, or you can export them as JSON null values.