Free · Browser local · Multiple files
JSON to Parquet Converter
Choose JSON files, get Parquet downloads
1. Choose files → 2. Convert in your browser → 3. Preview and download.
Add as many files as you need. Up to 16 MiB per file. Keep this tab open until your downloads finish.
Conversion starts as soon as you choose files. Files download automatically when ready. Your browser may ask to allow multiple downloads.
Files stay in your browser. Each file may contain up to 100,000 rows, 250,000 cells and 16 MiB of decoded text. Results may be up to 64 MiB. Downloads include every row; files over these limits show an error.
From JSON to Parquet
Choose files together and follow each result in the list. Conversion runs in your browser without sending the file to a server. Each download includes the complete converted table in its original row order.
Values are written as text so identifiers, decimals and large integers remain readable. Nested lists and objects become JSON text. This changes the format and does not preserve the original physical column schema.
Choose a JSON array of objects. Object keys become columns. Missing keys become null. Numeric text is preserved without rounding, including integers larger than JavaScript can represent exactly.
Plain answers
JSON to Parquet questions
How do I convert JSON to Parquet?
Choose one or more JSON files. Each file starts converting immediately in your browser. Preview and download each complete Parquet result when it is ready.
Are my files uploaded?
No. This converter runs locally in your browser. No account is needed. Keep the tab open until you have saved the results.
Are column types preserved?
This converter produces text columns to keep dates, decimals and large integers readable without rounding. Null values remain null in JSON, JSON Lines, Parquet and Avro. Nested values become JSON text. It does not preserve the original Parquet physical schema.
How large can my files be?
Each input may be up to 16 MiB, with up to 100,000 rows, 250,000 cells and 16 MiB of decoded text. Each result may be up to 64 MiB. Larger files show an error instead of a truncated download. The separate Parquet to CSV converter supports larger files.