Sitespeed.io
sitespeed.io is an open-source tool for comprehensive web performance analysis, enabling you to test, monitor, and optimize your website’s speed using real browsers in various environments.
Install / Use
/learn @sitespeedio/Sitespeed.ioREADME
sitespeed.io
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Table of Contents
- Welcome to the Wonderful World of Web Performance
- Installation
- Usage
- Examples
- Contributing
- Reporting Issues
- Community and Support
- License
Welcome to the wonderful world of web performance!
Welcome to sitespeed.io, the comprehensive web performance tool designed for everyone passionate about web speed. Whether you're a developer, a site owner, or just someone curious about website performance, sitespeed.io offers a powerful yet user-friendly way to analyze and optimize your website.
What is sitespeed.io?
sitespeed.io is more than just a tool; it's a complete solution for measuring, monitoring, and improving your website's performance. Built with simplicity and efficiency in mind, it enables you to:
- Test Websites Using Real Browsers: Simulate real user interactions and conditions to get accurate performance data.
- Speed Optimization Feedback: Get detailed insights into your website's construction and discover opportunities for enhancing speed.
- Track Performance Over Time: Monitor changes and trends in your website's performance to stay ahead of potential issues.
Use cases on when to use sitespeed.io.
- Web performance audit: Run performance tests from your terminal.
- Continuous Integration: Detect web performance regressions early in the development cycle.
- Production Monitoring: Monitor performance in production and get alerted on regressions.
Why Choose sitespeed.io?
- Open Source and Community-Driven: Built and maintained by a community, ensuring continuous improvement and innovation.
- Versatile and Extensible: Whether you're running a simple blog or a complex e-commerce site,
sitespeed.ioadapts to your needs. - Seamless Integration: Easily incorporate
sitespeed.iointo your development workflow, continuous integration systems, and monitoring setups.
Dive Into Our Documentation
We've put countless hours into our documentation to help you get the most out of sitespeed.io. From installation guides to advanced usage scenarios, our documentation is a treasure trove of information and tips.
Installation
Getting started with sitespeed.io is straightforward. You can install it using Docker or NodeJS, depending on your preference and setup. Follow these simple steps to begin optimizing your website's performance.
Docker
Using Docker is the easiest way to get started with sitespeed.io, especially if you don't want to handle dependencies manually. Run the following command to use sitespeed.io in a Docker container:
docker run --rm -v "$(pwd)":/sitespeed.io sitespeedio/sitespeed.io https://www.sitespeed.io/
This command pulls the latest sitespeed.io Docker image and runs a test on the sitespeed.io website. The -v "$(pwd)":/sitespeed.io part mounts the current directory into the container, allowing you to easily access test results.
NodeJS
If you prefer installing sitespeed.io as an npm package, ensure you have NodeJS installed on your system. Then, install sitespeed.io globally using npm:
npm i -g sitespeed.io
After installation, you can start using sitespeed.io by running:
sitespeed.io https://www.example.com
Replace https://www.example.com with the URL you wish to test. Note that using NodeJS might require additional dependencies like FFmpeg and Python. Detailed installation instructions for these dependencies can be found here.
Choose the method that best suits your environment and get ready to dive into web performance optimization with sitespeed.io!
Usage
sitespeed.io is tailored to be user-friendly, making web performance testing accessible regardless of your technical expertise. Here's a straightforward guide to help you begin your web performance optimization journey.
Basic Usage
To start testing your website, simply run sitespeed.io with the URL of the site you want to analyze. For example:
sitespeed.io https://www.example.com --browser chrome -n 5
This command tests https://www.example.com using Chrome and performs 5 iterations of the test. This approach helps in obtaining a more accurate median performance measurement by testing the site multiple times.
Advanced Configuration
sitespeed.io offers a wide range of configuration options to tailor the tests to your specific needs. You can specify different browsers, adjust connectivity settings, and much more. For a comprehensive list of all available options, visit our configuration documentation.
Additionally, for a quick overview of all command-line options, you can run:
sitespeed.io --help
This command displays all the available flags and settings you can use with sitespeed.io, helping you fine-tune your performance testing to fit your unique requirements.
Whether you're running a quick check or a detailed analysis, sitespeed.io provides the flexibility and power you need to deeply understand and improve your website's performance.
Mobile Performance Testing
In today's mobile-first world, ensuring your website performs optimally on smartphones and tablets is crucial. With sitespeed.io, you can simulate and analyze the performance of your website on mobile devices, helping you understand and improve the user experience for mobile audiences.
Why Test on Mobile?
- User Experience: A significant portion of web traffic comes from mobile devices. Testing on mobile ensures your site is optimized for these users.
- Search Engine Ranking: Search engines like Google prioritize mobile-friendly websites in their search results.
- Performance Insights: Mobile devices have different performance characteristics than desktops, such as CPU limitations and network variability.
How sitespeed.io Helps
- Real Browser Testing: Simulate mobile browsers to get accurate performance data as experienced by real users.
- Device-Specific Metrics: Gain insights into how your site performs on different mobile devices and networks.
- Responsive Design Analysis: Test how well your site adapts to various screen sizes and orientations.
Getting Started
To start testing your website’s mobile performance, you need to setup your mobile phone for testing. We got documentation for setting up your Android phone and iOS.
When your setup is ready, you can run tests on your Android phone.
sitespeed.io https://www.example.com --android
Examples
sitespeed.io provides insightful HTML reports that help you visualize and understand your website's performance. Here are some examples to illustrate what you can achieve:
Summary Report
Here's an example of a summary report in HTML, offering a comprehensive overview of your site's performance metrics:

This report includes key performance indicators like load times, page size, and request counts, giving you a quick snapshot of your site’s overall health.
Individual Page Report
For more detailed analysis, here's an individual page report:

This report dives deeper into a single page's performan
