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CSV Column Type Inferencer

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Parse CSV or TSV data and infer each column's data type (integer, float, boolean, ISO 8601 date, or string), flagging which columns are nullable and how many empty cells each one has.

Paste CSV or TSV data and see the data type each column actually holds: integer, float, boolean, ISO 8601 date, or string, based on classifying every non-empty value and finding the tightest type that fits them all. A column mixing integers and decimals infers as float, and any value that doesn't fit a narrower type falls the whole column back to string. Empty cells don't change the inferred type but do mark a column nullable, with a count of how many rows are missing that field. This is useful before writing a schema, a database migration, or an import script by hand, since it tells you up front which columns are clean numeric or boolean data and which ones are effectively free text.

csvdatatype-inferencevalidationschema

How to use CSV Column Type Inferencer

  • 1.Paste your CSV or TSV data, or upload a file.
  • 2.Adjust the delimiter or toggle whether the first row is a header, if needed.
  • 3.Read the inferred type, nullability, and sample values for each column in the results table.

Frequently asked questions

What counts as a date?
Only ISO 8601 dates and datetimes, like 2024-01-01 or 2024-06-15T10:30:00Z. Locale-specific formats like 01/06/2024 aren't recognized as dates and will infer as string.
Why did a column of numbers infer as string?
If even one value in that column doesn't parse as a number (a stray label, a unit suffix, an empty-looking value with extra characters), the whole column falls back to string, since it isn't reliably typed data.
Does mixing integers and decimals in one column count as an error?
No, that's a normal and common case, so it infers as float rather than being flagged as inconsistent.
Does this validate the data, or just describe it?
It only describes the shape of the data that's already there. It doesn't check the values against a schema you define, flag outliers, or fix anything.

Use via API, SDK, or MCP

cURL# Free: 1,000 req/day · Pro: 10,000 req/day
curl -X POST https://api.utilix.tech/v1/tools/csv-column-type-inferencer \
  -H "Authorization: Bearer utx_live_..." \
  -H "Content-Type: application/json" \
  -d '{"csv":"id,name,price,active\n1,Widget,9.99,true\n2,Gadget,19.5,false","delimiter":","}'

Get an API key from your dashboard · Full API docs →

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