# Search for Nix packages
One great thing about Nix is that there are *tons* of [packages] available in the [Nix ecosystem][ecosystem] that you can use in [Nix development environments][env], in your [NixOS][nixos] installations, and more.
While [Nixpkgs] is by far the largest Nix package collection—over 100,000 packages and counting :sunglasses:—any [Nix flake][flakes] can provide package [outputs].
But navigating all of this plenty can be tricky, so in this guide we'll learn how to search for packages in Nixpkgs using the [`nix search`][nix-search] command and using the web application at [search.nixos.org][search].
Then we'll learn how to explore packages in [other flakes](#nix-flake-show).
## The `nix search` command \{#nix-search-command}
The [Nix CLI][nix] has a `search` command that you can use to search the packages in a flake based on a search term.
Let's start by searching [Nixpkgs], which is where we're mostly likely to find packages we want.
This command will tell us if [cargo] is available in [Nixpkgs]:
```shell title="Search Nixpkgs using cargo as the search term"
nix search "https://flakehub.com/f/NixOS/nixpkgs/*" cargo
```
In this command, the `nixpkgs` [flake reference][flake-ref] is shorthand for `github:NixOS/nixpkgs`.
The first time you run `nix search`, the Nix CLI needs to download the full
Nix code contents of [Nixpkgs]—or whichever flake you're
searching—and then cache it. Future `nix search` runs for Nixpkgs should
be much speedier. Furthermore, Nixpkgs is the largest flake in existence and
running `nix search` on other flakes should be much faster in general.
This brings up many results of the form `legacyPackages.{system}.{package}`, the first of which should look like this on an Apple Silicon (`aarch64-darwin`) system:
```shell title="Example search result"
* legacyPackages.aarch64-darwin.cargo (1.65.0)
Downloads your Rust project's dependencies and builds your project
```
The system attribute [varies](#system-specificity) on other platforms (you may see `x86_64-linux` or something else).
After that first result, you should see many others, including packages like [`cargo-about`][cargo-about] and [`cargo-audit`][cargo-audit].
The `legacyPackages` attribute that you see in the search output is a bit misleading.
The [packages] prefaced with that aren't "legacy" packages; instead, [Nixpkgs] uses a special `legacyPackages` attribute to output packages instead of the usual `packages` output for reasons laid out in [this code comment][legacy-comment].
You can also output search results as JSON using the `--json` flag:
```shell title="Output search results as JSON"
nix search --json nixpkgs cargo
```
This can be useful if you want to parse the output using a tool like [jq].
## search.nixos.org \{#web}
The web interface at [search.nixos.org][search] has a few advantages over the [`nix search`](#nix-search-command) command:
- It enables you to select a release channel for [Nixpkgs], such as [25.05] and [unstable]
- It enables you to search across a range of [public flakes][public-flakes] beyond Nixpkgs (those flakes are listed [in the Nix manual][flakes-list])
## Exploring a flake with the `nix flake show` command \{#nix-flake-show}
As an example, let's explore a popular flake for the [Wayland] window system protocol.
```shell title="Display the flake outputs for the nixpkgs-wayland flake"
nix flake show "github:nix-community/nixpkgs-wayland"
```
You can also display the outputs as JSON:
```shell title="Display the flake outputs for the nixpkgs-wayland flake as JSON"
nix flake show --json "github:nix-community/nixpkgs-wayland"
```
The first time you run `nix flake show`, the Nix CLI needs to download the
full contents of [`nixpkgs-wayland`][nixpkgs-wayland]—or whichever flake
you're running `nix flake show` on—and then cache it. Future `nix flake
show` runs for the same [flake reference][flake-ref] should be much speedier.
Should you use `nix flake show` or `nix search`? A good rule of thumb is to
always use `nix search` with Nixpkgs and to initially use `nix flake show`
with other flakes. If the package outputs for `nix flake show` are big enough
to be tricky to navigate, use `nix search` for that flake instead.
## System specificity
One thing you'll notice about the search output for `nix search`, [search.nixos.org][search], and `nix flake show` is that all the packages listed in the query results are for your current system (`x86_64-linux` for an AMD/Intel Linux system, `aarch64-darwin` for an Apple Silicon system, and so on).
That's because Nix works in a fundamentally [system-specific] way.
The `cargo` package on a Linux machine is considered a *different package* from `cargo` on a non-Linux system.
[25.05]: https://github.com/nixOS/nixpkgs/tree/25.05
[cargo]: https://github.com/rust-lang/cargo
[cargo-about]: https://github.com/EmbarkStudios/cargo-about
[cargo-audit]: https://github.com/RustSec/rustsec/tree/main/cargo-audit
[ecosystem]: /concepts/ecosystem
[env]: /concepts/dev-env
[flake-ref]: /concepts/flakes#references
[flakes]: /concepts/flakes
[flakes-list]: https://github.com/NixOS/nixos-search/blob/main/flakes/manual.toml
[jq]: https://stedolan.github.io/jq
[legacy-comment]: https://github.com/NixOS/nixpkgs/blob/fcc8ff7cc271c9652623dae2a9fcd1ba49232b57/flake.nix#L47-L55
[nix]: /concepts/nix
[nix-search]: https://nixos.org/manual/nix/stable/command-ref/new-cli/nix3-search
[nixos]: /concepts/nixos
[nixpkgs]: /concepts/nixpkgs
[nixpkgs-wayland]: https://github.com/nix-community/nixpkgs-wayland
[outputs]: /concepts/flakes#outputs
[packages]: /concepts/packages
[public-flakes]: https://search.nixos.org/flakes
[search]: https://search.nixos.org
[system-specific]: /concepts/system-specificity
[unstable]: https://github.com/nixOS/nixpkgs/tree/nixpkgs-unstable
[wayland]: https://wayland.freedesktop.org