A month ago, we told you about the release of Speedometer 3.0, a new web performance testing benchmark that aims to provide a fairer, more representative measure of how a web browser performs modern web tasks. Unlike previous versions of Speedometer, which were created more or less by Apple’s WebKit team, version 3.0 is the result of a collaboration between Apple, Google, Microsoft and Mozilla with a new governance model to put itself agree on which tests are important representations of the modern web. .
In other words, it’s probably the “fairest” and most up-to-date measure of web browser performance we currently have.
WebKit is the rendering engine used by Safari and provided to Apple developers who want to use web rendering in their applications. It should be used by all browsers on iOS or iPadOS, except those in the EU. Apple’s WebKit development team has published a blog post detailing how it used Speedometer 3.0 as a guide to optimize the performance of Safari 17 (released September 2023) and Safari 17.4 (released March 2024).
Over those six months, many small, incremental improvements made a big difference. As the blog post summarizes:
With all of these optimizations and dozens more, we were able to improve the overall Speedometer 3.0 score by approximately 60% between Safari 17.0 and Safari 17.4. Although individual gains were often less than 1%, over time they all added up to make a big difference. Since some of these optimizations also benefited Speedometer 2.1, Safari 17.4 is also approximately 13% faster than Safari 17.0 on Speedometer 2.1.
WebKit blog post
Some of these improvements include things like bundling composition layer updates, increasing cache size on macOS, improving inline and SVG layout, and much more. Many of these improvements are minor, bringing just a few percentage points here or there, or targeting very specific parts of web performance. But several small improvements that have been added over time have resulted in a much faster browser.
This doesn’t mean that Safari is much faster than other Mac browsers. When we tested Speedomenter 3.0 last month, we were using Safari 17.4 and found that it was the fastest browser, but by only a very small margin. Edge still had some catching up to do, but Chrome and Firefox both just behind Safari’s speedometer score.
