Sitespeed.io

sitespeed.io is a web performance analysis tool and monitoring system designed to measure website speed and Core Web Vitals using real browsers. It functions as a performance regression suite and a browser performance monitor, enabling the enforcement of performance budgets to detect and block speed regressions.

The project is distinguished by its real device testing framework, which executes performance audits on physical Android and iOS hardware via USB connections. It includes a specialized tool for generating and comparing HTTP Archive files to diagnose network bottlenecks, alongside integration for executing Lighthouse audits to capture page quality and accessibility metrics.

The system covers a broad range of capabilities, including synthetic speed auditing, network traffic analysis, and continuous performance testing. It provides observability tools for tracking device power consumption, estimating environmental impact, and exporting time-series data to external databases for long-term trend monitoring.

Tests can be managed via a command-line interface or a web-based deployment system using JSON-driven configurations.

Features

Browser Performance Collectors - Drives real browser instances to capture Core Web Vitals and network waterfalls for authentic analysis.
Web Performance Metrics - Measures Core Web Vitals and generates network waterfalls to identify performance bottlenecks in web applications.
Web Performance Monitoring - Tracks website speed and core web vitals over time using real browsers to detect regressions and trends.
Performance Regression Analyzers - Compares current performance metrics against historical baselines to identify significant speed regressions.
Web Performance Monitors - Ships a monitoring system that tracks web speed trends over time using time-series databases and scheduled tests.
Mobile Device Bridges - Controls physical Android and iOS devices via USB to gather hardware-level power and browser metrics.
Real Device Testing - Executes performance tests on physical mobile hardware via bridge tools and device-specific work queues.
HAR File Analyzers - Processes HTTP Archive files to summarize network requests and calculate page load statistics.
HAR File Exporters - Captures all network requests from a browser session and exports them as standardized HAR files.
HAR File Processing - Converts raw network archive files into readable formats for detailed performance auditing.
Performance Threshold Enforcement - Enforces performance budgets by failing tests in CI pipelines when metrics exceed predefined thresholds.
Lighthouse Performance Scorers - Executes Google Lighthouse audits to capture Core Web Vitals and page quality scores.
Client-Side Performance Isolation - Isolates client-side performance from server latency by recording and replaying website content through a local proxy.
Metric-Based Regression Testing - Automates performance checks in CI pipelines to fail builds when metrics exceed defined speed budgets.
Synthetic Performance Auditing - Generates detailed reports and network waterfalls using Lighthouse and real browsers to identify page optimization opportunities.
Web Performance Regression Suites - Implements a continuous integration tool that enforces performance budgets to detect and block speed regressions.
Web Performance Optimization Tools - Measures website speed and Core Web Vitals using real browsers and automated tests.
Virtual Page Tracking - Monitors browser performance observers to track route changes in single-page applications as distinct page loads.
Web Archive Importers - Supports loading web archive files via upload or URL for performance analysis.
Time Series Export - Exports collected performance metrics to external time-series databases like Graphite for long-term monitoring.
HAR File Analysis Tools - Provides a utility for generating, processing, and comparing HTTP Archive files to diagnose network bottlenecks.
Network Traffic Analyzers - Processes and compares HAR files to analyze resource loading behavior and identify third party script bottlenecks.
HAR Summarization - Converts detailed network archives into compact JSON summaries aggregating request counts and sizes.
Performance Degradation Alerts - Sends notifications via communication tools when performance metrics drop below or exceed defined speed budgets.
Trace Comparison - Provides side-by-side analysis of network archive files to detect performance regressions between different site versions.
Performance Trend Analysis - Performs scheduled testing and exports metrics to time-series databases to track speed trends via dashboards.
Frontend Performance Dashboards - Provides real-time dashboards to track frontend performance metrics and compare page speeds against competitors.
Accessibility Auditing Tools - Includes automated scanners for detecting accessibility violations to ensure websites meet inclusivity standards.
Viewport and User Agent Simulation - Configures specific viewports and user agents to emulate mobile devices and test responsive performance.
Browser Performance Emulation - Simulates mobile device characteristics and CPU throttling on desktop browsers to approximate mobile user experience.
Network Condition Simulation - Simulates various connectivity levels to replicate real-world browsing experiences on different network conditions.
Network Latency Isolation - Records and replays website content through a local proxy to isolate front-end performance from server fluctuations.
Performance Test Orchestration - Provides a web-based and CLI interface for triggering performance tests on a dedicated server.
Soft Navigation Monitoring - Records single-page application route changes as separate pages by monitoring browser performance observers.
Continuous Testing - Integrates with scheduling tools and pipelines to trigger automated performance tests and generate reports.
User Journey Playback - Records and replays complex interaction sequences to verify specific functional paths and user flows.
Visual Performance Recording - Records browser screen video to calculate visual-based performance metrics such as Speed Index.
Request Impact Monitoring - Monitors the impact of external scripts and services on page load times and overall performance.

GoogleChrome/lighthouse-ci

6,996View on GitHub

Lighthouse CI is a continuous integration tool designed to automate web audits and detect performance, accessibility, and SEO regressions between code commits. It functions as a web performance regression suite that enforces resource budgets and runs automated quality checks during the software development lifecycle. The system distinguishes itself through the ability to block code merges if performance metrics fall below defined quality thresholds. It provides mechanisms for commit-to-commit comparison and cross-version site analysis to pinpoint specific resource improvements or regressions.

GoogleChrome/web-vitals

8,534View on GitHub

This project is a web performance monitoring library designed to collect, calculate, and attribute user experience metrics. It functions as a real user monitoring tool that tracks core loading and interactivity metrics from actual browser sessions to quantify website health and identify speed bottlenecks. The library includes a performance attribution engine that collects diagnostic data to pinpoint the root causes of page lag. This allows for the identification of specific performance bottlenecks alongside the measurement of core web vitals. The system provides comprehensive data export cap

gatling/gatling

6,923View on GitHub

Gatling is a load testing framework and traffic generation engine used to measure response times and error rates under heavy load. It functions as an as-code testing library, allowing users to define high-volume traffic simulations and performance tests through programming languages rather than graphical interfaces. The system enables multi-language load simulation and the ability to model concurrent user traffic to identify infrastructure bottlenecks and stability limits. It supports a test-as-code workflow, where version-controlled scripts are integrated into build pipelines as performance

grafana/k6

30,874View on GitHub

k6 is a performance testing framework used to measure the scalability and stability of network services and APIs. It functions as a JavaScript load testing tool that uses a Go engine to simulate concurrent user traffic. The tool enables the enforcement of service level objectives by comparing response time percentiles against quantitative performance thresholds. It also operates as a performance regression tool for continuous integration pipelines and a browser performance testing tool that executes scripts within a bundled headless browser instance. Its capabilities cover workload scenario

sitespeediositespeed.io

Features

Open-source alternatives to Sitespeed.io

GoogleChrome/lighthouse-ci

GoogleChrome/web-vitals

gatling/gatling

grafana/k6

Star history

Open-source alternatives to Sitespeed.io

GoogleChrome/lighthouse-ci

GoogleChrome/web-vitals

gatling/gatling

grafana/k6