CSV to JSON Converter

CSV vs JSON — when to use each

CSV (Comma-Separated Values) is ideal for tabular data in spreadsheets, database exports, and data science pipelines. It is compact and human-readable for flat data. JSON (JavaScript Object Notation) is preferred for APIs, web apps, and data with nested structures. Converting from CSV to JSON is a common step when importing spreadsheet data into a JavaScript or Node.js application.

What the output looks like

Given this CSV:

name,age,city
Alice,30,Mumbai
Bob,25,Delhi

The JSON output will be:

[
  { "name": "Alice", "age": "30", "city": "Mumbai" },
  { "name": "Bob", "age": "25", "city": "Delhi" }
]

Note: all values are strings in the output. If you need numeric types, apply JSON.parse with a reviver or use a library like Zod for type coercion.

Also see

Need the reverse operation? JSON to CSV Converter converts a JSON array back into a downloadable CSV file.

Common use cases for CSV to JSON conversion

Data engineers import exported spreadsheets from tools like Google Sheets or Tally into Node.js pipelines by converting CSV to JSON first. Frontend developers seed mock APIs and local state with JSON arrays derived from CSV data files. QA engineers convert test data tables from Excel into JSON fixtures for automated test suites. Analysts working with Python pandas can export DataFrames to CSV and then convert to JSON for downstream JavaScript processing. Product teams configure content-managed websites by authoring data in Google Sheets and converting to JSON for static site generators.

Handling type coercion — strings vs numbers

CSV has no native type system — all values are strings. When converting to JSON, all values appear as string literals even if they look like numbers or booleans. For example, the CSV value 30 becomes the JSON string "30" rather than the number 30. If your downstream code expects typed values, apply a transformation after conversion: in JavaScript use +row.age or Number(row.age) to coerce numeric fields; use row.active === 'true' to coerce booleans. Libraries like Zod and Valibot make this safe with schema validation at parse time.

How delimiter detection works

The four delimiters supported (comma, tab, semicolon, pipe) cover the vast majority of real-world CSV files. Comma is standard for most English-locale exports. Semicolons appear in European-locale Excel and LibreOffice exports where the comma is used as the decimal separator. Tab-separated values (TSV) are common in database exports and scientific data files. Pipe-delimited files are used in some EDI (electronic data interchange) and financial data formats. Select the correct delimiter before converting — mismatched delimiters will produce a single-column output instead of multiple columns.