parqview

Keyboard-first terminal UI for exploring Parquet, CSV, JSON, JSONL, and NDJSON files with DuckDB-backed preview and profiling.

Why This Exists

parqview is for fast inspection of parquet, csv, json, jsonl, and ndjson files.

Key features:

• select a set of columns and toggle visibility
• copy the selected columns as Python list literal
• copy the active cell value from the data pane
• search column names
• summaries of column data
• fast vim-inspired keyboard navigation and scrolling
• predicate filtering
• stacked column sorting in the table pane
• visual indication of missing data in rows and columns, jump to next missing value
• missing definition can toggle between NULL+NaN, NULL, NaN
• adaptive column width controls with an expanded reader for long text columns and structured JSON payloads
• resize panels with the mouse
• fast mouse scrolling

Use it to quickly catch:

• unexpected feature values
• unexpected NULLs or NaNs
• join failures (duplicate columns, mismatched keys, broken join coverage),

The aim is to provide smooth, low-friction, interactive data browsing with familiar and intuitive keyboard navigation.

Screenshot

Installation

Homebrew (recommended)

brew install robince/tap/parqview

Direct download from GitHub Releases

Download the archive for your platform from https://github.com/robince/parqview/releases.

macOS arm64 example:

VERSION="1.6.0"
curl -fL -o parqview.tar.gz "https://github.com/robince/parqview/releases/download/v${VERSION}/parqview_${VERSION}_darwin_arm64.tar.gz"
tar -xzf parqview.tar.gz
./parqview --version

Linux amd64 example:

VERSION="1.6.0"
curl -fL -o parqview.tar.gz "https://github.com/robince/parqview/releases/download/v${VERSION}/parqview_${VERSION}_linux_amd64.tar.gz"
tar -xzf parqview.tar.gz
./parqview --version

Note for direct macOS downloads: if Gatekeeper blocks first run, remove quarantine:

xattr -dr com.apple.quarantine ./parqview

Run

Open a file directly:

./parqview <file.parquet|file.csv|file.json|file.jsonl|file.ndjson>

Start with a specific row displayed:

./parqview +250 <file.parquet|file.csv|file.json|file.jsonl|file.ndjson>

Or run from source:

go run ./cmd/parqview <file.parquet|file.csv|file.json|file.jsonl|file.ndjson>

The +row argument can appear before or after the file path. Row numbers are 1-based immutable source row numbers.

If the app starts without a file, press Ctrl+O to open the file picker.

JSON support uses DuckDB's default auto-detection readers:

• .json uses read_json_auto
• .jsonl and .ndjson use read_ndjson_auto
• nested LIST and STRUCT values are preserved as DuckDB returns them

Screens and Keys

Shortcuts below describe app-specific behavior. When a search input is focused, normal text editing keys are handled by the Charmbracelet Bubbles textinput component.

Global commands

These keys are global commands that work whichever pane has focus.

Key	Action
Tab	Switch focus between table and columns panes
Ctrl+O	Open/close file picker (.parquet/.csv/.json/.jsonl/.ndjson)
q, Ctrl+C	Quit
Ctrl+L	Redraw screen
?	Open/close help overlay
m	Cycle missing mode (NULL+NaN → NULL only → NaN only)
s, S	Toggle selected-columns view in data table
v, V	Toggle selected-columns view in columns pane (columns focus)
Enter	Open detail panel for active column
Space	Page down in focused pane

Columns Pane

Use this pane to search, triage, and build a selection set of columns.

Key	Action
/	Focus column search input
Up, k	Move cursor up 1 row
Down, j	Move cursor down 1 row
Space, Ctrl+F	Page down
Ctrl+B	Page up
Ctrl+D	Half-page down
Ctrl+U	Half-page up
g, Home	Jump to top of full list
G, End	Jump to bottom of full list
H	Jump to top of current visible list window
M	Jump to middle of current visible list window
L	Jump to bottom of current visible list window
x	Toggle selection on active (crosshair) column
a	Add all filtered columns to selection
d	Remove all filtered columns from selection
A	Select all columns
X	Clear all selected columns
y	Copy selected columns as a Python list, or active column name if none selected
Enter	Open detail panel for active column

Table Pane

Use this pane to inspect row values, navigate missingness, and filter the current result set.

Key	Action
Up, k	Move row cursor up
Down, j	Move row cursor down
Left, h	Move selected column left
Right, l	Move selected column right
0	Jump to first visible table column
$	Jump to last visible table column
[	Page table columns left
]	Page table columns right
w	Toggle fit-width for ordinary values, or open the expanded reader when the visible column sample is too wide/multiline
Ctrl+W	Toggle global wide-columns mode
gg	Jump to top row
G	Jump to bottom row
[count]gg, [count]G	Jump to row number count
Space, Ctrl+F	Page down
Ctrl+B	Page up
Ctrl+D	Half-page down
Ctrl+U	Half-page up
<	Add or update ascending sort on selected column
>	Add or update descending sort on selected column
y	Copy active cell value
=	Open predicate prompt for selected column
p	Pin current cell value as an exact-match predicate
-	Clear predicate for selected column
U	Reset table transforms (predicates, missing-row filter, and sorts)
r	Jump to next missing value in current row
R	Jump to previous missing value in current row
c	Jump to next row with missing value in selected column
C	Jump to previous row with missing value in selected column
f	Toggle missing-row filter
Enter	Open detail panel for selected column

Predicate prompt examples:

• string columns: abc123, != abc123, %foo%, foo%, %foo, != %foo%
• numeric columns: 42, != 42, > 10, >= 10, < 10, <= 10, 10..20

Predicate notes:

• = opens the prompt prefilled with the current predicate for that column, or the active cell value when no predicate exists yet.
• p applies an exact-match predicate from the active cell without opening the prompt.
• %foo% matches contains, foo% matches prefixes, and %foo matches suffixes.
• Lowercase string patterns use case-insensitive matching (ILIKE); any uppercase character switches to case-sensitive matching (LIKE).
• % is the supported wildcard syntax for string patterns.
• _ and \_ both mean a literal underscore.
• Comparisons (>, >=, <, <=, a..b) require a numeric column.
• Multiple column predicates combine with AND.
• Reapplying a predicate on a column replaces the previous predicate for that column.
• Sorts stack in the order you apply them; reapplying < or > on a sorted column updates its direction without changing its priority.
• Row jumps still use immutable source row numbers and resolve within the current filtered/sorted result.

Column Search Input (in Columns Pane)

Key	Action
Esc	Clear query and exit search
Enter	Commit query and exit search
Ctrl+U	Clear search query
Text editing keys	Edit search query

Detail Panel Overlay

Key	Action
t	Cycle tabs (Top Values, Stats, Histogram)
n	Jump to first missing value for detail column
Esc, q	Close detail panel

Expanded Reader Overlay

Use this overlay for long text cells, JSON payloads, and other values that do not fit comfortably in the table.

The reader supports two content modes:

• raw for the sanitized original cell text
• json pretty for valid JSON object/array strings, with formatted indentation and light semantic color

When a string cell contains valid JSON object/array text, the reader opens in json pretty mode by default. Otherwise it opens in raw.

Key	Action
Up, k	Scroll up
Down, j	Scroll down
Left, h	Pan left when wrap is off
Right, l	Pan right when wrap is off
n, p	Move to next/previous row in the same column
F	Cycle reader format (raw / json pretty when available)
W	Toggle wrap
Space, Ctrl+F	Page down
Ctrl+B	Page up
Ctrl+D	Half-page down
Ctrl+U	Half-page up
g	Jump to top of current cell
G	Jump to bottom of current cell
Esc, q, w	Close expanded reader

Notes:

• json pretty is available only for valid JSON object/array strings; scalar JSON values stay in raw.
• Pretty JSON defaults to wrap off so indentation and horizontal panning stay readable.
• If you move rows with n or p, the reader keeps the current mode when the next row supports it and falls back to raw otherwise.

File Picker Overlay

Key	Action
Enter	Open selected file/folder
Backspace	Go to parent folder (when query is empty)
Ctrl+U	Clear picker query
Esc	Close file picker

Predicate Prompt Overlay

Key	Action
Enter	Apply predicate
Ctrl+U	Clear prompt input
Esc	Cancel

Help Overlay

Key	Action
Esc, ?, q	Close help

Mouse

Action	Behavior
Mouse wheel	Scroll cursor in focused pane
Left-drag divider	Resize table/columns split

Technical Details: Missing Definition

parqview has a runtime missing-value mode, toggled with m, with three states:

• NULL+NaN (default),
• NULL only,
• NaN only.

The active mode is shown in the top-right status badge and affects:

• missing indicators and missing cell styling,
• missing-row filter (f),
• missing navigation (n, r/R, c/C),
• missing counts in profiling and footers.

For categorical profiling, the active missing mode determines which values are excluded.

For numeric stats and histograms, parqview always profiles only finite numeric values. That means:

• NULL is excluded from numeric stats/histograms even in NaN only,
• NaN is excluded from numeric stats/histograms even in NULL only.