codspeed

Optimize code performance and catch regressions early.

Get Started · Documentation

Key features

• 🎯 <1% variance in measurements using CPU simulation - no more flaky benchmarks.
• 🔥 Differential flamegraphs to pinpoint exactly what got slower, commit by commit.
• 💬 PR comments & status checks showing performance impact directly in your workflow.
• 🛡️ Merge protection to block PRs that degrade performance beyond your threshold.
• 🐍 Multi-language support for Python, Rust, Node.js, Go, C/C++ and more.
• 🏠 Run locally or in CI - works on your machine and integrates with GitHub Actions, GitLab CI, and more.
• 🔌 Plug your existing benchmarks in less than 5 minutes - works with pytest, vitest, criterion, and more.

Installation

curl -fsSL https://codspeed.io/install.sh | bash

[!NOTE] The CodSpeed CLI officially supports Ubuntu 20.04, 22.04, 24.04 and Debian 11, 12. Other Linux distributions may work, but are not officially supported.

Quick Start

First, authenticate to keep your benchmark results linked to your CodSpeed account:

codspeed auth login

The simplest way to get started is to benchmark any executable program directly:

# Benchmark a single command
codspeed exec -- ./my-binary --arg1 value

# Benchmark a script
codspeed exec -- python my_script.py

# Benchmark with specific instrument
codspeed exec --mode walltime -- node app.js

This approach requires no code changes and works with any executable. CodSpeed will measure the performance provide the instrument results.

Deeper integration with harnesses using codspeed run

For more control and integration with your existing benchmark suite, you can use language-specific harnesses. This allows you to:

• Define multiple benchmarks and keep them versioned in your codebase
• Scope benchmarks to specific functions or modules
• Integrate with existing benchmark suites (pytest, criterion, vitest, etc.)

# Using the Rust harness with criterion
codspeed run cargo codspeed run

# Using the Python harness with pytest
codspeed run pytest ./tests --codspeed

# Using the Node.js harness with vitest
codspeed run pnpm vitest bench

These harnesses provide deeper instrumentation and allow you to write benchmarks using familiar testing frameworks.

Languages Integrations

CodSpeed provides first-class integrations for multiple languages and frameworks: