Speedometer 3.0: The Joint Effort to Benchmark Web Browsers

This article explores the Speedometer benchmark, a critical tool used to measure web browser responsiveness, and examines the unprecedented collaboration between Apple, Google, and Mozilla to create Speedometer 3.0. By uniting the rival teams behind the Safari web browser, Chrome, and Firefox, this joint effort establishes a modern, unbiased standard for evaluating real-world web application performance and improving the internet experience for all users.

What is the Speedometer Benchmark?

Speedometer is a browser benchmark tool originally created by Apple’s WebKit team in 2014. Its primary purpose is to measure the responsiveness of a web browser by simulating real-world user interactions on web applications.

Instead of testing raw computing power in isolation, Speedometer loads simulated web apps—historically, various implementations of "to-do" list applications—and automatically performs actions like adding, completing, and deleting items. By timing how fast a browser can execute these simulated clicks and keystrokes, Speedometer evaluates the performance of the browser's JavaScript engine, layout rendering, CSS styling, and Document Object Model (DOM) manipulation all at once.

Why Apple Collaborated with Google and Mozilla

For years, browser makers developed their own performance benchmarks. However, this created a major industry problem: companies often tailored their benchmarks to favor their own browser engines, or they over-optimized their browsers simply to get a high score on a specific test without actually improving real-world performance.

To solve this, Apple (makers of the WebKit engine used in the Safari web browser), Google (makers of the Blink engine used in Chrome), and Mozilla (makers of the Gecko engine used in Firefox) formed a cross-industry collaboration to develop Speedometer 3.0.

The reasons for this collaboration include:

  • Neutral Governance: By establishing a strict rule that major changes require consensus from all three browser engines, no single company can manipulate the test to give its browser an unfair advantage.
  • Reflecting the Modern Web: The web has evolved significantly since the release of Speedometer 2.0 in 2018. The three companies pooled their data and engineering expertise to identify which modern frameworks and code patterns are actually being used across the internet today.
  • Shared Goals: Regardless of competition, Apple, Google, and Mozilla all benefit when the open web is fast and responsive. A unified benchmark gives web developers a single, reliable metric to target.

How Speedometer 3.0 Evaluates the Safari Web Browser and Others

Speedometer 3.0 is a massive upgrade over previous versions, moving far beyond basic to-do lists to test how browsers like the Safari web browser handle today's complex digital workloads.

First, the benchmark incorporates updated versions of today’s most popular web development frameworks, including React, Vue, Angular, Preact, Lit, and Svelte. This ensures that when Apple engineers use Speedometer 3.0 to test the Safari web browser, they are optimizing it for the exact tools modern web developers use to build websites.

Second, Speedometer 3.0 introduces a much wider variety of simulated user tasks. The test suite now evaluates how quickly a browser can:

  • Render complex charts and dashboards.
  • Load and navigate heavy content websites, such as news portals.
  • Process rich text and code editing applications.
  • Handle complex HTML5 canvas rendering and CSS layouts.

Finally, Speedometer 3.0 changes how performance is timed. Previous versions missed some of the asynchronous work a browser does behind the scenes. The new benchmark measures the entire lifecycle of a user interaction—from the moment a simulated button is clicked, through the JavaScript execution, to the exact millisecond the updated pixels are painted onto the user's screen.

By using Speedometer 3.0, Apple, Google, and Mozilla can accurately pinpoint bottlenecks in their respective engines. For users of the Safari web browser, Chrome, and Firefox, this collaboration translates directly into faster page loads, smoother scrolling, and a more responsive everyday web experience.