Skip to content


Switch branches/tags

Name already in use

A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?

Latest commit

Bumps [github/codeql-action]( from 2.3.5 to 2.3.6.
- [Release notes](
- [Changelog](
- [Commits](github/codeql-action@0225834...83f0fe6)

- dependency-name: github/codeql-action
  dependency-type: direct:production
  update-type: version-update:semver-patch

Signed-off-by: dependabot[bot] <>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]>

Git stats


Failed to load latest commit information.
Latest commit message
Commit time

What is Miller?

Miller is like awk, sed, cut, join, and sort for data formats such as CSV, TSV, JSON, JSON Lines, and positionally-indexed.

What can Miller do for me?

With Miller, you get to use named fields without needing to count positional indices, using familiar formats such as CSV, TSV, JSON, JSON Lines, and positionally-indexed. Then, on the fly, you can add new fields which are functions of existing fields, drop fields, sort, aggregate statistically, pretty-print, and more.


  • Miller operates on key-value-pair data while the familiar Unix tools operate on integer-indexed fields: if the natural data structure for the latter is the array, then Miller's natural data structure is the insertion-ordered hash map.

  • Miller handles a variety of data formats, including but not limited to the familiar CSV, TSV, and JSON/JSON Lines. (Miller can handle positionally-indexed data too!)

In the above image you can see how Miller embraces the common themes of key-value-pair data in a variety of data formats.

Getting started

More documentation links


There's a good chance you can get Miller pre-built for your system:

Ubuntu Ubuntu 16.04 LTS Fedora Debian Gentoo

Pro-Linux Arch Linux


Anaconda Homebrew/MacOSX MacPorts/MacOSX Chocolatey

OS Installation command
Linux yum install miller
apt-get install miller
Mac brew install miller
port install miller
Windows choco install miller

See also for a full list of package versions. Note that long-term-support (LtS) releases will likely be on older versions.

See also building from source.


GitHub stars Homebrew downloads Conda downloads

All Contributors

Build status

Multi-platform build status CodeQL status Codespell status

Building from source

  • First:
    • cd /where/you/want/to/put/the/source
    • git clone
    • cd miller
  • With make:
    • To build: make. This takes just a few seconds and produces the Miller executable, which is ./mlr (or .\mlr.exe on Windows).
    • To run tests: make check.
    • To install: make install. This installs the executable /usr/local/bin/mlr and manual page /usr/local/share/man/man1/mlr.1 (so you can do man mlr).
    • You can do ./configure --prefix=/some/install/path before make install if you want to install somewhere other than /usr/local.
  • Without make:
    • To build: go build
    • To run tests: go test and mlr regtest.
    • To install: go install will install to GOPATH/bin/mlr.
  • See also the doc page on building from source.
  • For more developer information please see

For developers


License: BSD2


  • Miller is multi-purpose: it's useful for data cleaning, data reduction, statistical reporting, devops, system administration, log-file processing, format conversion, and database-query post-processing.

  • You can use Miller to snarf and munge log-file data, including selecting out relevant substreams, then produce CSV format and load that into all-in-memory/data-frame utilities for further statistical and/or graphical processing.

  • Miller complements data-analysis tools such as R, pandas, etc.: you can use Miller to clean and prepare your data. While you can do basic statistics entirely in Miller, its streaming-data feature and single-pass algorithms enable you to reduce very large data sets.

  • Miller complements SQL databases: you can slice, dice, and reformat data on the client side on its way into or out of a database. You can also reap some of the benefits of databases for quick, setup-free one-off tasks when you just need to query some data in disk files in a hurry.

  • Miller also goes beyond the classic Unix tools by stepping fully into our modern, no-SQL world: its essential record-heterogeneity property allows Miller to operate on data where records with different schema (field names) are interleaved.

  • Miller is streaming: most operations need only a single record in memory at a time, rather than ingesting all input before producing any output. For those operations which require deeper retention (sort, tac, stats1), Miller retains only as much data as needed. This means that whenever functionally possible, you can operate on files which are larger than your system’s available RAM, and you can use Miller in tail -f contexts.

  • Miller is pipe-friendly and interoperates with the Unix toolkit.

  • Miller's I/O formats include tabular pretty-printing, positionally indexed (Unix-toolkit style), CSV, TSV, JSON, JSON Lines, and others.

  • Miller does conversion between formats.

  • Miller's processing is format-aware: e.g. CSV sort and tac keep header lines first.

  • Miller has high-throughput performance on par with the Unix toolkit.

  • Miller is written in portable, modern Go, with zero runtime dependencies. You can download or compile a single binary, scp it to a faraway machine, and expect it to work.

What people are saying about Miller

Today I discovered Miller—it's like jq but for CSV:

Also, "Miller complements data-analysis tools such as R, pandas, etc.: you can use Miller to clean and prepare your data." @GreatBlueC @nfmcclure

— Adrien Trouillaud (@adrienjt) September 24, 2020

Underappreciated swiss-army command-line chainsaw.

"Miller is like awk, sed, cut, join, and sort for [...] CSV, TSV, and [...] JSON."

— Dirk Eddelbuettel (@eddelbuettel) February 28, 2017

Miller looks like a great command line tool for working with CSV data. Sed, awk, cut, join all rolled into one:

— Mike Loukides (@mikeloukides) August 16, 2015

Miller is like sed, awk, cut, join, and sort for name-indexed data such as CSV: - handy tool!

— Ilya Grigorik (@igrigorik) August 22, 2015

Btw, I think Miller is the best CLI tool to deal with CSV. I used to use this when I need to preprocess too big CSVs to load into R (now we have vroom, so such cases might be rare, though...)

— Hiroaki Yutani (@yutannihilat_en) April 21, 2020

Miller: a *format-aware* data munging tool By @__jo_ker__ to overcome limitations with *line-aware* workshorses like awk, sed et al

The project website is a fantastic example of good software documentation!!

— Donny Daniel (@dnnydnl) September 9, 2018

Holy holly data swiss army knife batman! How did no one suggest Miller for solving database cleaning / ETL issues to me before

Congrats to @__jo_ker__ for amazingly intuitive tool for critical data management tasks!#DataScienceandLaw #ComputationalLaw

— James Miller (@japanlawprof) June 12, 2018

🤯@__jo_ker__'s Miller easily reads, transforms, + writes all sorts of tabular data. It's standalone, fast, and built for streaming data (operating on one line at a time, so you can work on files larger than memory).

And the docs are dream. I've been reading them all morning!

— Benjamin Wolfe (he/him) (@BenjaminWolfe) September 9, 2021


Thanks to all the fine people who help make Miller better (emoji key):

Andrea Borruso

🤔 🎨

Shaun Jackman


Fred Trotter

🤔 🎨





Thomas Klausner


Stephen Kitt


Leah Neukirchen


Luigi Baldoni


Hiroaki Yutani


Daniel M. Drucker


Nikos Alexandris




Victor Sergienko


Adrian Ho




David Selassie


Joel Parker Henderson


Michel Ace


Matus Goljer


Richard Patel


Jakub Podlaha


Miodrag Milić


Derek Mahar




Peter Körner












Fulvio Scapin


Jordan Torbiak


Andreas Weber






Brian Fulton-Howard




Jauder Ho


Paweł Sacawa





📖 🤔

This project follows the all-contributors specification. Contributions of any kind are welcome!