DuckCSV

High-performance CSV/TSV/Parquet viewer powered by DuckDB. Edit, query, filter, and profile your data directly in VS Code.

Features

View & Navigate

• Instant rendering — Open files with millions of rows. Virtual scrolling keeps it smooth.
• Parquet support — Open .parquet files alongside CSV/TSV.
• Auto-delimiter detection — Comma, semicolon, tab, pipe — detected automatically.
• Sticky headers — Column headers stay visible as you scroll.
• Column types — DuckDB infers types (INTEGER, VARCHAR, DATE, etc.) and displays them in the header.

Edit

• Cell editing — Double-click any cell to edit. Type changes are handled automatically.
• Row operations — Insert rows above/below, delete single or multiple rows via right-click.
• Undo/Redo — Full undo history with Cmd+Z / Cmd+Shift+Z.
• Save — Cmd+S writes back to the original file. Save As for a new file.

Sort, Filter & Search

• Column sort — Click header arrows for ascending/descending sort.
• Column filters — Funnel icon opens a dropdown with unique values. Multi-select to filter.
• Global search — Search across all columns with highlighting. Debounced for performance.

SQL Queries

• DuckDB SQL — Write queries in the built-in query bar. Full DuckDB SQL support.
• Inline or side panel — Run queries inline (replaces current view) or in a separate panel.
• Autocomplete — Column names and table names autocomplete as you type.
• Query history — Access previous queries from the history dropdown.

Multi-Table Workspace

• Load multiple files — Open the workspace and load multiple CSV/TSV/Parquet files.
• JOIN across files — Run SQL JOINs between tables like a local database.
• Table switching — Switch between loaded tables with the dropdown.

Data Profiling

• Column stats — Click the 📊 button on any column header to see: total rows, non-null count, unique values, null %, min, max, mean, median, std dev.
• Selection stats — Select cells in a single column to see count, sum, avg, min, max in the status bar. Calculated via SQL on the full dataset.

Copy & Export

• Excel-like selection — Click cells, drag rows/columns, Shift+click for ranges.
• Copy with headers — Cmd+C copies selection with headers and file delimiter.
• Export — Export query results or filtered data to CSV/TSV/Parquet.

Getting Started

1. Open any .csv, .tsv, or .parquet file
2. Click the table icon in the top-right corner of the editor
3. That's it — you're in

Commands:

• DuckCSV: Open Preview — open the current file as an interactive table
• DuckCSV: Open Workspace — load multiple files and query across them

Keyboard shortcuts:

• Cmd+K V — Open preview for the current file
• Cmd+S — Save changes
• Cmd+Shift+S — Save As (choose format)
• Cmd+Z / Cmd+Shift+Z — Undo / Redo
• Cmd+C — Copy selection
• Cmd+Enter — Run query inline
• Cmd+Shift+Enter — Run query in side panel
• Arrow keys / Tab — Navigate between cells
• Double-click cell — Edit cell

Requirements

• VS Code 1.106.0+
• No external tools needed — DuckDB WASM is bundled

License

Apache 2.0 — see LICENSE

Acknowledgments

Thanks to Christophe Ricco for the support and feedback during development.