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CSV to JSON Converter

Convert tabular data between CSV and JSON with quoted-field handling, validation, copy, and download.

The CSV Assumptions That Break Conversions

CSV has no official standard, which is why edge cases dominate: fields containing commas must be quoted, embedded quotes get doubled, and line breaks can live inside quoted fields — any of these silently misaligns naive parsers and produces wrong JSON. Encoding is the other trap: a CSV exported from Excel in Spanish or German often arrives in Windows-1252, and accented characters become mojibake when read as UTF-8. Check one converted row against the source before trusting a bulk conversion.

Headers Become Keys

When the first row is a header, each following row becomes an object with the column names as keys, which is the shape most APIs and front-end code expect. Duplicate or empty header names collide, so rename them first.

CSV carries no types, so every value is a string unless converted: 007 and 1e3 can be misread if turned into numbers, so keep identifiers as text. Converting JSON to CSV works best for flat arrays of objects, since nested objects have to be flattened.

How the Tool Processes Your File

  1. Paste CSV with a header row, or paste a JSON array of objects, choosing the conversion direction.
  2. The parser handles quoted fields, embedded commas, and multiline values correctly instead of splitting naively.
  3. A validation step flags malformed rows or inconsistent keys before you commit to the output.
  4. Copy the result to the clipboard or download it as a .csv or .json file.

Typical Use

CSV to JSON for an API
Input: name,email,city Ana,ana@x.com,Madrid Luis,luis@x.com,Barcelona
Output: [{"name":"Ana","email":"ana@x.com","city":"Madrid"},{"name":"Luis","email":"luis@x.com","city":"Barcelona"}]
The header row becomes the JSON keys, and each subsequent row becomes an object — the exact shape most REST APIs and databases expect.
JSON to CSV for a spreadsheet
Input: [{"id":1,"status":"active"},{"id":2,"status":"pending"}]
Output: id,status 1,active 2,pending
Converting API responses to CSV lets you open the data in Excel or Google Sheets for quick reporting.

Common Questions

Are quoted CSV fields handled?

Yes. Values wrapped in double quotes that contain commas, quotes, or newlines are parsed exactly as the RFC 4180 CSV specification describes.

What happens if the JSON is a nested structure?

Nested objects are stringified into their JSON representation inside the cell. For clean spreadsheet output, flatten the structure before converting.

Is large data supported?

The converter runs fully in-browser and processes files up to the memory limit of your device — comfortably into the hundreds of thousands of rows.

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