What's new in DevTools, Chrome 127

Sofia Emelianova

Inspect CSS anchor positioning in the Elements panel

To help you debug anchor positioning feature easier, the Styles tab now links explicit anchor identifiers and implicit anchors to their nodes.

The before and after linking explicit and implicit anchors.

Additionally, the popovertarget attribute value now links to its popover element in the DOM.

The before and after linking popovertarget to its popover element.

Chromium issue: 289900232, 330306231.

Sources panel improvements

This version brings several improvements to the Sources panel.

Enhanced 'Never Pause Here'

The 'Never Pause Here' option lets you prevent the Debugger from pausing on the same line again and again. This makes it easier to work with irrelevant breakpoints that fire repeatedly. This version enhances this capability and it now works for:

Exceptions or promise rejections from built-in functions.
"Canceling" DOM, fetch/XHR, and CSP Violation breakpoints.
In Wasm disassembly.

See the workflow in action:

Chromium issue: 40924349.

New scroll snap event listeners

The Sources > Event Listener Breakpoints > Control list gets two scroll-snap-related listeners: scrollsnapchange and scrollsnapchanging. These events fire when you scroll the scroll container in a way that would cause it to snap to a new element.

The before and after adding scroll-snap-related event listeners.

Chromium issue: 40286359.

Network panel improvements

This version brings several improvements to the Network panel.

Updated network throttling presets

The Network panel gets updated throttling presets: new Fast 4G, Fast 3G renamed to Slow 4G, and Slow 3G renamed to 3G. This better aligns with Lighthouse's presets.

The before and after updating network throttling presets.

Chromium issue: 342406608.

Service worker information in custom fields of the HAR format

When exporting the network log into a HAR format, you can now see the information related to service workers, including timings, as custom fields (prefixed by underscores). For example, you might find the following new fields in the log:

...
"response": {
  ...
  "_fetchedViaServiceWorker": true,
  "_responseCacheStorageCacheName": "V1",
  "_serviceWorkerResponseSource": "cache-storage"
}
...
"timings": {
  ...
  "_workerStart": -1,
  "_workerReady": -1,
  "_workerFetchStart": -1,
  "_workerRespondWithSettled": -1
}
...

Chromium issue: 342406608.

Send and receive WebSocket events in the Performance panel

Similar to other WebSocket events, the Performance panel now captures Send WebSocket Message and Receive WebSocket Message events and shows them in the performance trace. For example:

The 'Receive WebSocket Message' event captured in the performance trace.

Chromium issue: 40286129.

Miscellaneous highlights

These are some noteworthy fixes and improvements in this release:

Accessibility: Screen readers now announce the content of messages in the Console when scrolling through the log with up and down arrow keys (344484979).
Sources:
- Page: The Save as menu option now saves Wasm module files as valid wasm binaries instead of Base64 text (40784130).
- Call stack: Removed the (async) suffix from Async call frame descriptions, changed their highlight from italic to bold (343750870).
Memory: Removed the unnecessary zero-sized InternalNodes from heap snapshot Summary (340200025).
Network: Fixed a bug that prevented the preview of streaming response content for requests that just started but didn't get a responseReceived event yet (338340752).
Performance:
- Selector Stats: Added an explanatory tooltip for the %-of-Slow-Path-Non-Matches column (324282954).
- Track configuration mode: The Finish configuring tracks button has been moved to the bottom right side (345256274).
Console: Fixed a bug that showed multiple identical console messages when navigating using the back/forward-cache (40894153).
Settings: Added helper icons next to all tabs (330213867).

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Consider using the Chrome Canary, Dev or Beta as your default development browser. These preview channels give you access to the latest DevTools features, test cutting-edge web platform APIs, and find issues on your site before your users do!

Getting in touch with the Chrome DevTools team

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