Fast interactive CSV viewer for the terminal

csvview is a TUI application for working with large CSV files, written in C using ncurses. No Python, no Electron, no dependencies — a single binary with instant startup and minimal memory usage. Works over SSH on any server.

Handles files with up to 50 million rows using memory-mapped I/O and multithreaded processing (up to 8 threads). Opens CSV, TSV, PSV, NDJSON with automatic delimiter detection.

Install

macOS via Homebrew:

Or build from source:

Quick start

When launched without arguments, a recent files picker opens showing file size, row count, column count and file type.

Navigation

Move through the table with arrow keys or vim-style (h j k l). gg — jump to start, G — jump to end. Ctrl+G or :N — go to line by number. PageUp/PageDown for paging. z — freeze columns on the left.

Navigation stays smooth even on multi-million-row files — data is read via mmap directly from disk without loading the entire file into memory.

Search

Press / and type your search query. All matches are highlighted in the table and matching rows are marked with * in the gutter. n / N — jump to next/previous result.

Filtering & sorting

f — quick filter on the current column. Shift+F — advanced filter with expressions:

Supported operators: =, !=, >, >=, <, <=, logic: AND, OR, !. Dates can be filtered by month (= 2025-01) or quarter (= 2025-Q3).

Sorting: [ — ascending, ] — descending. { / } — add a sort level for multi-level sorting.

Column statistics

Press d on any column. For numeric columns: sum, mean, median, mode, min/max, top 10 values and a distribution histogram. For dates: breakdown by month, quarter, year.

Additional views: p — percentiles (P1–P99, IQR, stddev), e — trends (sparkline across 20 time buckets), f — full frequency list with navigation and drill-down.

Correlation matrix (:corr) shows Pearson r for all numeric columns with color coding. Press Enter on a cell to open a scatter plot of those two columns.

Outlier report (:outliers) finds rows where |z-score| exceeds a threshold. Enter — jump to row, f — apply filter.

Charts

Press g on a numeric column to build a chart right in the terminal. Types: line, bar, dot. Charts are rendered using braille Unicode characters — each terminal character carries 2×4 pixels.

Scatter plot (:gsc) to visualize the relationship between two columns with Pearson r calculation. Dual Y axis (:g2y) to overlay two metrics with different scales. Donut chart (Ctrl+G on a text column) for frequency distribution. Box plot (:gbox) to compare distributions.

All charts can be exported to SVG with :gsvg — a ready-made file for print or documentation.

Pivot tables

Press p to build a pivot table. In the settings window choose:

• Rows / Columns — columns for row and column grouping
• Values — column to aggregate
• Aggregation — SUM, AVG, COUNT, MIN, MAX, UNIQUE COUNT and combinations
• Date grouping — Month, Quarter, Year, Century (for date columns)
• Filter by — a 3rd dimension (Report Filter)

The result is an interactive pivot table with navigation, totals, and current cell highlighting:

Show Values As (v) — switch display: absolute values → % of row → % of column → % of grand total → rank → running total.

Report Filter (F) — popup for selecting values of the 3rd dimension. * marks selected values, Space toggles. < / > — quick single-value cycling.

Sparklines (S) — braille trend chart next to each row. Transpose (T) — instantly swap rows and columns.

Graph (G) — split-screen: table on the left, chart on the right. Space — pin a series, a — toggle axis, s — linear/log scale.

Drill-down: press Enter on a pivot cell — the main table opens filtered by that cell's row and column values.

Export: :e — CSV, :em — Markdown, :eg — SVG chart. Pivot row filtering: :ptop 10, :pbot 5, :pfilter >1000.

Editing

Enter — edit a cell. u — undo (up to 20 steps). s — save changes to file.

Column management: :cr name — rename, :cd name — delete, :cal / :car name — add left/right, :dr N — delete row.

Computed columns (:cf) — add a column with a formula:

Available functions: round, abs, floor, ceil, mod, pow, if, empty. Aggregates: col_sum, col_avg, col_min, col_max, col_count, col_median, col_percentile, col_stddev, col_var, rank, pct.

Themes

10 color themes: dark, light, tokyonight, nord, catppuccin, solarized_light, paper, turbovision, dracula, gruvbox. Pick with :theme (live preview) or from the command line with --theme=name.

CLI tools

csvview works not only as an interactive viewer but also as a set of CLI utilities:

Open source, MIT license. Repository: github.com/daniil-khanin/csvview