Parquet vs CSV for Property Data
Both formats hold the same properties. The difference is what they carry, how big they are, and how fast they query.
The short answer
Use Parquet if you're analyzing data in code (pandas, DuckDB, Polars, Spark) or you want the full schema including price and tax history. Use CSV if you want to open it in a spreadsheet or feed a tool that only speaks CSV.
What each carries
- Parquet — all 32 columns, including the nested
price_historyandtax_historyarrays. A columnar, compressed binary format. - CSV — the same records as a flat table, minus the two nested history columns (a flat file can't hold arrays cleanly).
Size and speed
Parquet is columnar and compressed, so the same data is often several times smaller on disk than CSV, and queries that touch a few columns read only those columns — much faster on large files. CSV is row-oriented plain text: universally readable, but bigger and slower to scan.
Opening each
Parquet: pd.read_parquet("file.parquet") in pandas, or SELECT * FROM 'file.parquet' in DuckDB — no import step. CSV opens in Excel, Google Sheets, or any language's CSV reader. Full walkthrough in how to download property data.
Frequently asked
Should I download Parquet or CSV?
Can Excel open a Parquet file?
Why is Parquet smaller than CSV?
Does the CSV include price history?