> ## Documentation Index
> Fetch the complete documentation index at: https://codspeed.io/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# cargo-codspeed documentation
> The `cargo` subcommand to benchmark your Rust code with CodSpeed
export const BuildkiteIcon = props => ;
export const GitLabIcon = props => ;
export const GitHubIcon = props => ;
## Overview
`cargo-codspeed` is a Cargo subcommand for running performance benchmarks with
CodSpeed. It provides an easy way to build and run benchmarks for Rust projects
with CodSpeed integration.
## Installation
### With `cargo`
```bash theme={null}
cargo install cargo-codspeed --locked
```
### With `cargo-binstall` (recommended in CI)
[`cargo-binstall`](https://github.com/cargo-bins/cargo-binstall) enables you to
install binaries directly without having to build from the source(with
`cargo install`) every time.
If you don't have installed yet, you can install it with:
```bash theme={null}
cargo install cargo-binstall
```
You can then install `cargo-codspeed` with:
```bash theme={null}
cargo binstall cargo-codspeed
```
## Usage
### Building Benchmarks
Build your benchmarks for CodSpeed:
```bash theme={null}
cargo codspeed build
```
### Running Benchmarks
Run the previously built benchmarks:
```bash theme={null}
cargo codspeed run
```
### The `--measurement-mode` flag
When building benchmarks, you can specify the measurement mode using the
`--measurement-mode` / `-m` flag. This determines which CodSpeed instrument can
be used to run your benchmarks.
```bash theme={null}
# First build the benchmarks:
cargo codspeed build -m simulation
# Then run them:
cargo codspeed run -m simulation
```
The `--measurement-mode` flag can take the following values:
* **`simulation`**: Runs benchmarks once on a [simulated CPU](/instruments/cpu)
for consistent measurements.
* **`walltime`**: Measures [wall-clock time](/instruments/walltime) for
real-world scenarios.
* **`memory`**: Benchmarks are run once using
[memory profiling](/instruments/memory) to track heap allocations and memory
usage.
If you omit the `--measurement-mode` flag, the default behavior is to build for
simulation mode.
