# Install numdiff with Homebrew, apt, MacPorts, Nix

Putative files comparison tool. Version 5.9.0 via Homebrew; verified from local package data. Also installable with debian: sudo apt install numdiff.

## Install

```sh
sudo av install brew:numdiff
```

Additional install commands:

### macOS

- Homebrew (100%):

```sh
brew install numdiff
```

  Evidence: local Homebrew formula metadata

- MacPorts (94%):

```sh
sudo port install numdiff
```

  Evidence: MacPorts ports tree: science/numdiff/Portfile from https://api.github.com/repos/macports/macports-ports/git/trees/master?recursive=1

### Linux

- Debian apt (92%):

```sh
sudo apt install numdiff
```

  Evidence: Debian stable package indexes: numdiff from https://deb.debian.org/debian/dists/stable/main/binary-amd64/Packages.xz

- Nix (92%):

```sh
nix profile install nixpkgs#numdiff
```

  Evidence: nixpkgs package indexes: pkgs/by-name/nu/numdiff/package.nix from https://api.github.com/repos/NixOS/nixpkgs/git/trees/master?recursive=1

## Package facts

- **Package key:** brew:numdiff
- **Package manager:** Homebrew
- **Version:** 5.9.0
- **Source summary:** Putative files comparison tool
- **Homepage:** <https://www.nongnu.org/numdiff>
- **Generated:** 2026-08-03T19:37:03+00:00

## Executables

- ndselect (alias)
- numdiff (alias)

## Install behavior

- Bottle: not available

## Freshness

- Page generated: 2026-08-03
- Package-manager version: 5.9.0
## Project history and usage

Numdiff is a small, long-lived NonGNU utility by Ivano Primi for comparing files that contain numeric fields. Its reason to exist is simple: ordinary `diff`, `cmp`, and `wdiff` do not know that two textual representations may be numerically equivalent, nor can they ignore numeric changes below a requested tolerance.

### Project history

The official manual for Numdiff 5.9 carries copyrights from 2005 through 2017 and documents a mature Unix-style C program built with the usual `configure`, `make`, and `make install` workflow. The 5.9 manual also notes that older 5.x releases accepted fewer options and that 4.0.0 and 3.x used a different output format, so the package has a real pre-5.x history even though public narrative sources are sparse.

### Adoption history

Numdiff has modest adoption: it is packaged by Homebrew, Debian/Ubuntu, MacPorts, Nix, and GNU Guix, but it is not a broad ecosystem cornerstone. Homebrew's formula page listed only 43 installs over 365 days on July 1, 2026, which fits the profile of a specialist testing/scientific utility that users reach for when normal diffs are too literal.

### How it is used

The practical workflow is comparing generated numeric output line by line and field by field while setting absolute or relative tolerances and accepting equivalent numeric notation. Numdiff also ships `ndselect` for selecting lines and fields, and version 5.9 added a raw output format intended for machine parsing.

### Why package nerds care

Numdiff is the classic package-manager long tail: tiny, stable, GPL-licensed, and exactly useful when validating numerical programs whose outputs vary by rounding, notation, platform, compiler, or BLAS implementation. It is most likely to appear in regression-test scripts, scientific-code QA, and packaging test fixtures.

### Timeline

- 2005-2017: Years covered by the official manual copyright range.
- 5.9: Adds compact raw output intended for parsing by other programs.

### Related projects

- GNU diffutils
- wdiff
- cmp

### Sources

- <https://formulae.brew.sh/formula/numdiff>
- <https://packages.guix.gnu.org/packages/numdiff/5.9.0/>
- <https://www.nongnu.org/numdiff/>
- <https://www.nongnu.org/numdiff/numdiff.html>


## Security Notes

narrow executable package without higher-risk signals.

- **Geiger risk:** green / low
- narrow executable package without higher-risk signals

## Other Package-Manager Records

- Debian apt - numdiff - 5.9.0-2: normalized package name match | Debian stable package indexes: numdiff from https://deb.debian.org/debian/dists/stable/main/binary-amd64/Packages.xz | Compare similar files with numeric fields | https://nongnu.org/numdiff/
- Nix - numdiff: normalized package name match | nixpkgs package indexes: pkgs/by-name/nu/numdiff/package.nix from https://api.github.com/repos/NixOS/nixpkgs/git/trees/master?recursive=1
- Ubuntu apt - numdiff - 5.9.0-1: normalized package name match | Ubuntu 24.04 LTS package indexes: numdiff from https://archive.ubuntu.com/ubuntu/dists/noble/universe/binary-amd64/Packages.gz | Compare similar files with numeric fields | http://nongnu.org/numdiff/
- MacPorts - numdiff: normalized package name match | MacPorts ports tree: science/numdiff/Portfile from https://api.github.com/repos/macports/macports-ports/git/trees/master?recursive=1


## Combined YAML source

View the package source record on GitHub. [combined/numdiff.yml](https://github.com/mxcl/pkgdb/blob/main/combined/numdiff.yml)


## Sources

- pkg.so package database
- Geiger risk classifier
- curated package history
- pkgdb category and tag curation
- external package-manager database matches
- cross-ecosystem install command graph