Is converting Parquet to PostgreSQL free?

Yes. Files up to 10MB convert free with no account. There is a limit of five conversions per day per IP address.

Will my Parquet data keep its types in PostgreSQL?

Yes — that is the point. Whole numbers, decimals, dates and booleans are mapped to real PostgreSQL types rather than everything becoming text. The mapping table above shows exactly what you get.

Do you store my file?

No. The file is written to a temporary directory, converted, and the directory is deleted as soon as your download has been sent.

Convert Parquet to PostgreSQL

Upload a .parquet file and get back a PostgreSQL SQL script you can load straight into your database. Types are preserved rather than flattened to text. Free, no registration, up to 10MB.

1Upload your file

Click to upload or drag and drop

CSV, Excel, SQLite, SQL, DBF (max 10 MB)

2Choose target format

How your data is typed in PostgreSQL

Generated from the converter's own PostgreSQL type mapping — this is what it actually emits, not an example.

Your data	PostgreSQL type
Whole number	BIGINT
Decimal (money)	NUMERIC(10,2)
Floating point	DOUBLE PRECISION
True / false	BOOLEAN
Date	DATE
Date and time	TIMESTAMP
Short text	TEXT
Long text	TEXT
Binary data	BYTEA

Working from a .parquet file

Parquet is the one source here that arrives with a complete, machine-readable schema, so the conversion is a translation rather than an investigation. The interesting question is what Parquet can express that a SQL table cannot.

→Lists, structs and maps have no scalar equivalent in a relational target, so those columns are carried across as JSON text instead of being exploded into invented columns.
→Integer widths are kept rather than widened: int8 and int16 become a 16-bit column and int32 a 32-bit one, so the target schema stays as tight as the file was.
→A Parquet dataset is usually a directory of part files with partition keys encoded in directory names like year=2024/. One file is read, and a column that exists only as a directory name is not inside it.
→Rows are streamed in batches of 10,000, so a wide file never has to be held in memory all at once.

What the PostgreSQL script contains

The conversion produces one dump.sql with a README beside it, zipped. It is a script you can open, grep and edit before you run it rather than an archive a tool has to unpack, and it is deliberately sparing in what it declares.

→Every string column is declared TEXT, whatever length the source declared for it. PostgreSQL stores a short value in a TEXT column exactly as cheaply as in a VARCHAR, and an unbounded column cannot reject a row on load for being a few characters too long.
→Identifiers are all double-quoted, and even so a name on PostgreSQL's reserved list is given a trailing underscore: a column called user arrives as user_, order as order_, limit as limit_.
→A decimal column whose source declared no scale is given six decimal places rather than none, keeping whatever precision it did declare: NUMERIC(10,6) from a source that said 10, and NUMERIC(18,6) from one that declared neither. A scale of zero would have the server round 19.99 to 20 as it loaded.

Reading Parquet

→Parquet carries a full schema, so nothing is guessed — types, decimal precision and nullability are read directly.
→Decimal columns keep their exact precision and scale.

Writing PostgreSQL

→Backslashes are left alone, because PostgreSQL treats them as ordinary characters — doubling them would corrupt every Windows path.
→Auto-increment columns become GENERATED BY DEFAULT AS IDENTITY.
→Binary data is written as bytea, and identifiers respect the 63-character limit.

What you get

A ZIP containing dump.sql, plus a README with the exact command to load it. If anything about your data needed a judgement call, a _warnings.txt explains it.

Load this dump into PostgreSQL:

  psql -U USER -d DATABASE -f dump.sql

Create the database first if it does not exist:

  createdb -U USER DATABASE

Questions

Is converting Parquet to PostgreSQL free?: Yes. Files up to 10MB convert free with no account. There is a limit of five conversions per day per IP address.
Will my Parquet data keep its types in PostgreSQL?: Yes — that is the point. Whole numbers, decimals, dates and booleans are mapped to real PostgreSQL types rather than everything becoming text. The mapping table above shows exactly what you get.
Do you store my file?: No. The file is written to a temporary directory, converted, and the directory is deleted as soon as your download has been sent.