What are some tools that can be used to measure and analyze JavaScript performance?
TL;DR
To measure and analyze JavaScript performance, you can use tools like Chrome DevTools, Lighthouse, WebPageTest, and JSPerf. Chrome DevTools provides a Performance panel for profiling, Lighthouse offers audits for performance metrics, WebPageTest allows for detailed performance testing, and JSPerf helps in comparing the performance of different JavaScript snippets.
Tools to measure and analyze JavaScript performance
Chrome DevTools
Chrome DevTools is a set of web developer tools built directly into the Google Chrome browser. It provides a Performance panel that allows you to record and analyze the runtime performance of your web application.
- Open Chrome DevTools by pressing
F12orCtrl+Shift+I - Navigate to the Performance panel
- Click the "Record" button to start profiling
- Interact with your web application to capture performance data
- Click the "Stop" button to end profiling and analyze the results
Lighthouse
Lighthouse is an open-source, automated tool for improving the quality of web pages. It provides audits for performance, accessibility, progressive web apps, SEO, and more.
- Open Chrome DevTools
- Navigate to the Lighthouse panel
- Select the categories you want to audit (e.g., Performance)
- Click the "Generate report" button
- Review the generated report for performance insights and recommendations
WebPageTest
WebPageTest is a free online tool that provides detailed performance testing of web pages. It allows you to run tests from multiple locations around the world using real browsers.
- Go to WebPageTest
- Enter the URL of the web page you want to test
- Select the test location and browser
- Click the "Start Test" button
- Review the detailed performance report, including metrics like load time, time to first byte, and more
JSPerf
JSPerf is a tool for comparing the performance of different JavaScript snippets. It allows you to create and run benchmarks to see which code performs better.
- Go to JSPerf
- Create a new test case by entering different JavaScript snippets
- Run the benchmark to compare the performance of the snippets
- Review the results to see which snippet performs better