100% FREE & OPEN SOURCE

Dat.

The fastest data file viewer.

PARQUET · CSV · XLSX · TSV · JSON · SQLITE · DUCKDB

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Dat.

Open a file to start

Drop a file here, or open one from disk.

CSVTSVParquetJSON
0 rows0 cols—
Pick two multi-gigabyte files, open both in less than a second.

Speed through multi-gigabyte files.

Pick two multi-gigabyte CSV and Parquet files from disk. Both open as tabs in the same window, ready in less than a second.

Build a Pivot by dragging columns.

Group sales by region and category, drag to reverse their hierarchy, then change the revenue aggregation inside the Pivot popover.

Apply typed Filters over the grid.

Add typed filter chips over the grid. Combine conditions while keeping active filters and results in view.

Search finds it, even with a typo.

Search one column or all of them. Fuzzy matching still finds the word when the query is misspelled.

Join two files with SQL.

Every view is a DuckDB query you can edit. Join two open files, run it, and keep working from the result.

GOOD TO KNOW

Quick answers.

Is Dat free?
Yes, it's free and open source. No fees, no account, no subscriptions.
Does Dat collect my data?
No. Dat runs entirely on your computer and your datasets are never uploaded anywhere.
Is Dat safe?
Yes. The code is open source and anyone can audit it. Your files never leave your machine.