What it does
qsv is a Rust command-line toolkit for working with CSV and other tabular data. Its commands cover jobs such as counting rows, selecting or joining data, sorting, validating and converting files. The project also documents support for spreadsheet and columnar formats, plus SQL-style querying through its `sqlp` command. A developer can use it for a one-off check on an export or place several commands in a repeatable data-preparation pipeline.
Count first, then choose a transformation
A useful first check is qsv count test-results.csv. The command reports the number of CSV rows, which can catch an unexpectedly empty or oversized export before a script consumes it. From there, qsv's command set can select fields, remove duplicates, compare two files, sort rows, or perform SQL-style joins and queries with sqlp. For example, a developer could count a CI-generated results file, then keep only the columns needed for a small release report. The command example is illustrative and was not run for this listing.
qsv is a local CLI rather than a database server. Its site describes CSV plus formats such as Excel, OpenDocument spreadsheets, JSONL and Parquet; some commands can also move data into SQLite or PostgreSQL. This makes it a fit for file-based preparation and inspection, not a substitute for a database that owns application state. The homepage lists Linux, macOS and Windows binaries.
The browser demo is a different path
The official site has an alpha browser interface for demonstrating individual commands. Its count demo states a 1 MB maximum file size and warns users not to upload sensitive data. Treat that restriction as applying to the online demo, not to the locally installed CLI. For private exports or larger files, use the command-line program on a machine where the data belongs.
The current repository license is MIT. The site also links to a separately named qsv Pro offering; its service terms and prices were not assessed here.
Strengths
- Combines many common tabular-data operations in a command-line tool, including counting, filtering, joining and validation.
- Handles CSV and documents additional spreadsheet, JSONL and Parquet workflows, so small transformations can stay in one pipeline.
- Provides binaries for Linux, macOS and Windows.
Watch out for
- The optional browser command demo limits individual files to 1 MB and explicitly warns against uploading sensitive data; that is not a limit established for the CLI.
Best for
- Checking and cleaning CSV exports before a script or database import
- Joining, filtering or validating tabular files in a repeatable shell pipeline
- Exploring spreadsheet or Parquet data without building a separate application
Sources
- qsv official project site (Oct 26, 2026)
- qsv count browser demonstration (Oct 26, 2026)
- dathere/qsv official repository (Oct 26, 2026)
- qsv COPYING license file (Oct 26, 2026)