Free · Browser-local · No signup
Convert CSV to Parquet
Create a real Apache Parquet file from CSV locally, with one string column for every stable CSV header.
CSV → Parquet
The selected CSV and generated download stay in this browser tab.
Output contract
What the Parquet converter writes
Parquet stores data by column. This converter uses stable display headers as Parquet column names and writes every CSV cell with the STRING logical type to avoid silent type coercion.
The same 50 MB CSV input limit and production parser used by the viewer apply here. The generated file is created only after parsing succeeds.
Plain answers
Parquet conversion questions
Is this a real Parquet file?+
Yes. The browser uses a format-native writer to create a valid .parquet file, not a renamed CSV.
Is my CSV uploaded?+
No. The selected file is read and converted in this browser tab. Loading the page, code, or bundled sample still makes ordinary web requests.
What happens to data types?+
All source cells remain strings. This preserves identifiers and leading zeroes and avoids guessing that a date, boolean, or formula-like value has another meaning.