Data profile — column stats for your file
Drop a Parquet, Avro, CSV, TSV, JSON or JSONL file to get an instant per-column profile: type, null %, approximate distinct count, min/max, mean and median. It runs entirely in your browser (DuckDB-WASM) over the whole dataset — nothing is uploaded.
Drop a file or click to browse
Parquet, Avro, CSV, TSV, JSON, JSONL, XML, Excel — processed locally, never uploaded
Frequently asked questions
- What does the profile compute?
- Per column: the inferred type, null count and %, an approximate distinct count, min and max, and for numeric columns the mean and median — computed over the whole file, not a sample.
- How is the distinct count calculated?
- With DuckDB's approx_count_distinct (HyperLogLog) so it stays fast on large files. It's an estimate within a couple of percent, not an exact COUNT(DISTINCT).
- Which file types can I profile?
- Parquet, Avro, CSV, TSV, JSON, JSONL and Excel — anything the toolkit can read in the browser.
- Is my file uploaded?
- No. Profiling runs entirely in your browser with DuckDB-WASM; the file's contents never leave your device.