datasight

A terminal viewer for CSV and Parquet files with vim-style navigation, built with Rust and ratatui. Themed with Catppuccin Mocha.

Features

• Vim-style navigation (hjkl, g/G, PageUp/PageDown)
• Search within a column (/, n/N)
• Multi-column filtering with comparison operators — > 30, = Engineering, != 0 (f, F)
• Unique values popup — browse and filter by distinct values instantly (u)
• Sort by any column (s)
• Group-by with per-column aggregations (b, a, B)
• Column plot — line, bar, or histogram chart (p, t)
• Column Inspector — schema and stats for every column at a glance (i)
• Column stats popup (S)
• In-app help popup (?)
• Catppuccin Mocha color theme with zebra-striped rows and mode-aware status bar
• Supports CSV and Parquet files
• Viewport-windowed rendering — stays fast on large files

Install

Pre-built binaries (recommended)

Download the latest binary for your platform from the GitHub Releases page.

Build from source

Requires Rust 1.75 or higher.

cargo install --git https://github.com/SpollaL/datasight

Or clone and run locally:

cargo run -- <path-to-file.csv>
cargo run -- <path-to-file.parquet>

Keybindings

Navigation

Key	Action
j / Down	Move down
k / Up	Move up
h / Left	Move left
l / Right	Move right
g / Home	Jump to first row
G / End	Jump to last row
PageDown	Scroll down 20 rows
PageUp	Scroll up 20 rows

Search

Key	Action
/	Enter search mode (searches in current column)
Enter	Confirm search and jump to first match
n	Next match
N	Previous match
Esc	Exit search and clear results

Filter

Key	Action
f	Enter filter mode (filters rows by current column)
Enter	Confirm filter and return to normal mode
F	Clear all filters
Esc	Discard input

Supports comparison operators for numeric columns: > 30, < 100, >= 0, <= 50, = 42, != 0. Use = text or != text for exact string matching. Plain text falls back to substring search.

Unique Values

Key	Action
u	Open unique values popup for current column (sorted by frequency)
type	Search / filter the list live
j / k	Navigate the list
Enter	Apply selected value as a filter and close
Esc	Close without filtering

Sort

Key	Action
s	Sort by current column (toggles asc/desc)

Group By

Key	Action
b	Toggle group-by key for current column
a	Cycle aggregation for current column (Σ μ # ↓ ↑)
B	Execute group-by / clear and return to full view

Plot

Key	Context	Action
p	Normal	Mark current column as Y and enter pick-X mode
h / ← / l / →	Pick-X	Navigate to the X column
Enter	Pick-X	Confirm X column and show chart
Esc	Pick-X	Cancel and return to normal mode
t	Plot	Cycle chart type (line → bar → histogram)
Esc / p	Plot	Close chart and return to normal mode
q	Plot	Quit

Numeric X columns are plotted directly. String or date X columns use row indices as data points and render the actual values as rotated (vertical) labels below the chart — all labels are shown when they fit, otherwise they are sampled evenly.

For histogram, the Y column is binned automatically — no X column selection needed.

Column Inspector

Key	Action
i	Open Column Inspector (type, count, nulls, unique, min, max, mean, median)
j / k	Navigate rows
Enter	Jump to the selected column and return to data view
Esc / i	Close and return to data view

Column Stats

Key	Action
S	Toggle stats popup for current column (count, min, max, mean, median)

Other

Key	Action
i	Open Column Inspector
_	Autofit current column width
=	Autofit all columns
S	Toggle column stats popup
?	Toggle help popup
q	Quit

Troubleshooting

The display looks garbled or misaligned

Your terminal may not support 256 colors or Unicode box-drawing characters. Try a modern terminal emulator (kitty, alacritty, iTerm2, Windows Terminal) and make sure TERM is set to xterm-256color.

Columns are too narrow or too wide

Press = to autofit all columns to their content, or _ to autofit only the current column.

Filtering with >, <, >=, <= shows an error

These operators only work on numeric columns. Use = value or != value for exact string matching, or plain text for substring search.

The unique values popup shows fewer results than expected

The popup is capped at the 500 most frequent values. If your column has more than 500 distinct values, the title will say [top 500].

Large files are slow to open

datasight reads the entire file into memory on startup using Polars. In practice, load times are fast: a 42 MB / 1M-row CSV loads in under 0.1s using ~115 MB RAM. Multi-GB files will use proportionally more memory. Once loaded, navigation and filtering are fast regardless of row count.

Parquet file fails to open

Make sure the file is a valid Parquet file. Compressed or encrypted Parquet variants are not supported.