What's New In DevTools (Chrome 60)
Welcome! New features and major changes coming to DevTools in Chrome 60 include:
- A new Audits panel, including tests for progressive web apps, performance, accessibility, and best practices.
- Object previews in the Console.
- Real-time updates in the Coverage tab.
- A new menu for selecting contexts in the Console.
- Simpler network throttling options.
- Async stack traces on by default.
Note: You can check what version of Chrome you're running at
chrome://version. Chrome auto-updates to a new major version about every 6 weeks.
Check out the video version of these release notes below or read on to learn more.
New features #
New Audits panel, powered by Lighthouse #
The Audits panel is now powered by Lighthouse. Lighthouse provides a comprehensive set of tests for measuring the quality of your web pages.
The scores at the top for Progressive Web App, Performance, Accessibility, and Best Practices are your aggregate scores for each of those categories. The rest of the report is a breakdown of each of the tests that determined your scores. Improve the quality of your web page by fixing the failing tests.
Figure 1. A Lighthouse report
To audit a page:
- Click the Audits tab.
- Click Perform an audit.
- Click Run audit. Lighthouse sets up DevTools to emulate a mobile device, runs a bunch of tests against the page, and then displays the results in the Audits panel.
Lighthouse at Google I/O '17 #
Check out the DevTools talk from Google I/O '17 below to learn more about Lighthouse's integration in DevTools.
Note: The video should start playing at 32:30, which is when Paul discusses Lighthouse.
Contribute to Lighthouse #
Lighthouse is an open-source project. To learn lots more about how it works and how to contribute to it, check out the Lighthouse talk from Google I/O '17 below.
Third-party badges #
Figure 2. Hovering over a third-party badge in the Network panel
Figure 3. Hovering over a third-party badge in the Console
To enable third-party badges:
- Open the Command Menu.
- Run the
Show third party badgescommand.
Use the Group by product option in the Call Tree and Bottom-Up tabs to group performance recording activity by the third-party entities that caused the activities. See Get Started With Analyzing Runtime Performance to learn how to analyze performance with DevTools.
Figure 4. Grouping by product in the Bottom-Up tab
A new gesture for Continue to Here #
Say you're paused on line 25 of a script, and you want to jump to line 50. In the past, you could set a breakpoint on line 50, or right-click the line and select Continue to here. But now, there's a faster gesture for handling this workflow.
When stepping through code, hold Command (Mac) or Control (Windows, Linux) and then click to continue to that line of code. DevTools highlights the jumpable destinations in blue.
Figure 5. Continue To Here
Step into async #
A big theme for the DevTools team in the near future is to make debugging asynchronous code predictable, and to provide you a complete history of asynchronous execution.
The new gesture for Continue to Here also works with asynchronous code. When you hold Command (Mac) or Control (Windows, Linux), DevTools highlights jumpable asynchronous destinations in green.
Check out the demo below from the DevTools talk at I/O for an example.
Note: The video should start playing at 17:40, which is when Paul discusses the feature.
More informative object previews in the Console #
Previously, when you logged or evaluated an object in the Console, the Console would only display
Object, which is not particularly helpful. Now, the Console provides more information about the contents of the object.
Figure 6. How the Console used to preview objects
Figure 7. How the Console now previews objects
More informative context selection menu in the Console #
The Console's Context Selection menu now provides more information about available contexts.
- The title describes what each item is.
- The subtitle below the title describes the domain where the item came from.
- Hover over an iframe context to highlight it in the viewport.
Figure 8. Hovering over an iframe in the new Context Selection menu highlights it in the viewport
Real-time updates in the Coverage tab #
When recording code coverage in Chrome 59, the Coverage tab would just display "Recording...", with no visibility into what code was being used. Now, the Coverage tab shows you in real-time what code is being used.
Figure 9. Loading and interacting with a page using the old Coverage tab
Figure 10. Loading and interacting with a page using the new Coverage tab
Simpler network throttling options #
The network throttling menus in the Network and Performance panels have been simplified to include only three options: Offline, Slow 3G, which is common in places like India, and Fast 3G, which is common in places like the United States.
Figure 11. The new network throttling options
The throttling options have been tweaked to match other, kernel-level throttling tools. DevTools no longer shows the latency, download, and upload metrics next to each option, because those values were misleading. The goal is to match the true experience of each option.
Async stacks on by default #
The Async checkbox has been removed from the Sources panel. Async stack traces are now on by default. In the past, this option was opt-in, because of performance overhead. The overhead is now minimal enough to enable the feature by default. If you prefer to have async stack traces disabled, you can turn them off in Settings or by running the
Do not capture async stack traces command in the Command Menu.
DevTools at Google I/O '17 #
Check out the talk by the mythical Paul Irish below to learn more about what the DevTools team has been working on over the past year and the big themes that they're tackling in the near future.