Convert JSON to Parquet Online

Converting JSON to Parquet is a common step when archiving API response data, storing document exports, or building an analytical dataset from JSON sources. Parquet's columnar format and compression make it 5–10x smaller than equivalent JSON and dramatically faster to query with columnar engines like DuckDB, Athena, Spark, and BigQuery.

Use cases include storing bulk API response archives in a data lake, converting a MongoDB or Firestore export for analytics, compressing large JSON dump files for long-term storage, and preparing data for a cloud data warehouse. If you are paying for cloud storage and your data is currently stored as JSON, converting to Parquet will meaningfully reduce both storage costs and query times.

DuckDB infers column types from the JSON values — numbers become integers or doubles, booleans are preserved, strings remain strings. Nested objects and arrays in the JSON are stored as Parquet struct and list columns respectively, preserving the nested structure. If you need a fully flat Parquet schema, run the Flatten tool on your JSON file before converting.