Free CSV to TypeScript Converter — generate a typed interface from CSV columns in your browser

What Is CSV to TypeScript Conversion?

CSV to TypeScript conversion turns the columns of a CSV file into a typed interface describing one row of data. Each header becomes a property, and the converter infers the field type from the column values — a column of whole numbers becomes number, true/false becomes boolean, and anything else stays string. This gives you a ready-to-use type for loading CSV data into a typed codebase, instead of treating every field as a raw string.

How Type Inference Works

CSV itself carries no type information — every cell is text. To produce a professional interface, this tool scans all rows of each column and picks the narrowest type that fits the whole column:

  • number — every non-empty value is numeric (integer or decimal).
  • boolean — every value is true or false (any case).
  • string — the fallback for mixed, text, or empty columns.

Inference follows the same data-driven approach used by tools like quicktype, and the output follows the TypeScript interface syntax.

How to Use the CSV to TypeScript Converter

  • Paste CSV with a header row into the input, or load the example.
  • Click Convert to TypeScript to generate the interface.
  • Copy the result and drop it into your .ts file.

Common Use Cases

Type a CSV import in a Node or front-end project, scaffold a row model for a data-loading script, generate fixtures for tests, or quickly understand the shape of an unfamiliar spreadsheet — all without uploading your data anywhere.

Frequently Asked Questions

Does it detect numbers and booleans, or is everything a string?

It detects types. The converter checks every value in a column and emits number or boolean when the whole column qualifies; otherwise the field is string.

Does the output represent one row or the whole file?

One row. The interface describes a single record; in your code you would type the parsed CSV as an array of that interface (e.g. Row[]).

What if a column mixes numbers and text?

Mixed columns fall back to string, which is the safe, lossless choice — you can refine the type by hand afterwards.

Is my CSV uploaded to a server?

No. Conversion runs entirely in your browser — your data never leaves your device.