What's new in DevTools (Microsoft Edge 80)

To check out the latest features of Microsoft Edge DevTools and the Microsoft Edge DevTools extension for Microsoft Visual Studio Code and Visual Studio, read these announcements.

To stay up to date and get the latest DevTools features, download an Insiders preview version of Microsoft Edge. Whether you're on Windows, Linux, or macOS, consider using Canary (or another preview channel) as your default development browser. The Beta, Dev, and Canary versions of Microsoft Edge run as separate apps, side-by-side with the stable, released version of Microsoft Edge. See Microsoft Edge Insider Channels.

For the latest announcements, follow the Microsoft Edge team on Twitter. To report a problem with DevTools or ask for a new feature, file an issue in the MicrosoftEdge/DevTools repo.

Announcements from the Microsoft Edge DevTools team

Accessibility improvements to the DevTools

The DevTools team has contributed 170 changes to Chromium to address high-impact color contrast, keyboard, and screen reader issues in the DevTools. Every developer building the web should be able to use the DevTools.

The Performance tool in the DevTools with keyboard navigation and screen reader improvements

Want to learn how to make your web page accessible to all of your users? Download the Accessibility Insights and webhint extensions for Microsoft Edge to get started.

If you use screen readers or the keyboard to navigate around the DevTools, send your feedback by tweeting at us or selecting the Send Feedback icon!

Chromium issue #963183

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Using the DevTools in other languages

Many developers use other developer tools, like StackOverflow and Visual Studio Code, in their native language, not just in English. We're excited to announce localization for the DevTools, which you can now use in one of 10 languages besides English:

  • Chinese (Simplified) - 中文(简体)
  • Chinese (Traditional) - 中文(繁體)
  • French – français
  • German - deutsch
  • Italian - italiano
  • Japanese - 日本語
  • Korean - 한국어
  • Portuguese - português
  • Russian – русский
  • Spanish - español

Go to edge://flags and set the Enable localized Developer Tools flag to Enabled. Also set the Developer Tools experiments flag to Enabled. Restart Microsoft Edge and open the DevTools. The DevTools match the language you use for Microsoft Edge in edge://settings/languages.

The DevTools in German

If you want to use the DevTools in a different language than the ones that are available, tweet at us or click the Send Feedback icon.

Chromium issue #941561

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webhint Microsoft Edge extension

The webhint Microsoft Edge extension allows you to easily scan your web page and get feedback on accessibility, browser compatibility, security, performance, and more within the DevTools. Read more at https://webhint.io.

The Hints tool in the DevTools when the webhint browser extension is installed

Try the webhint browser extension in Microsoft Edge. Once you install the extension, open DevTools and then select the Hints tool. From here, run a customizable site scan. Head over to webhint.io to learn more.

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3D View

Use the 3D View to debug your web application by navigating through the Document Object Model (DOM) or the z-index stacking context.

The 3D View in DevTools

To access the 3D View, go to edge://flags and ensure that the Developer Tools experiments flag is set to Enabled. Restart Microsoft Edge and open the DevTools. Select F1 in the DevTools or open the Settings > Experiments section, and turn on the Enable 3D View checkbox. Now, press Ctrl + Shift + P, type in 3D View and select Show 3D View.

We're working on the UI and adding more functionality to the 3D View so please send us your feedback.

Chromium issue #987787

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Visual Studio Code extensions

The DevTools team has also released some extensions for Visual Studio Code that let you use the power of the DevTools directly from your text editor. Check out the following extensions.

Elements for Microsoft Edge

Use the Elements tool from within Visual Studio Code by adding the Elements for Microsoft Edge Visual Studio Code extension.

The Elements tool in Visual Studio Code using the Elements for Microsoft Edge extension

Update: As of 2022, the Elements for Microsoft Edge extension is now the Microsoft Edge DevTools extension for Visual Studio Code.

For more information, check out Microsoft Edge DevTools extension for Visual Studio Code.

Debugger for Microsoft Edge

With the Debugger for Microsoft Edge Visual Studio Code extension, debug JavaScript running in Microsoft Edge directly from Visual Studio Code.

The Debugger for Microsoft Edge Extension in Visual Studio Code

Update: As of 2022, the Debugger for Microsoft Edge Visual Studio Code extension has been replaced by a built-in debugger for Microsoft Edge in Visual Studio Code. See Debug Microsoft Edge in Visual Studio Code.

webhint

The webhint Visual Studio Code extension uses webhint to improve your web page while you're writing it! This extension runs and reports diagnostics on your workspace files based on webhint analysis.

The webhint Visual Studio Code extension analyzing a .tsx file in Visual Studio Code

Learn more about the Visual Studio Code webhint extension.

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Visual Studio integration

In Visual Studio 2019 version 16.2 or later, use the Visual Studio debugger to debug JavaScript running in Microsoft Edge. Download Visual Studio 2019 to try this feature out.

Visual Studio with the option to launch your web app in Microsoft Edge Canary, Dev, or Beta

Read our blog post to learn how to debug Microsoft Edge from Visual Studio.

To learn more about debugging Microsoft Edge from Visual Studio, see Visual Studio for web development.

Tracking prevention Console messages

Tracking prevention is a unique feature in Microsoft Edge that blocks you from being tracked by a website before you visited it. The default tracking prevention setting is Balanced mode, which blocks 3rd party trackers and known malicious trackers for an experience that balances privacy and web compatibility. To give you more insight into the compatibility of your web page when certain trackers are blocked, The Microsoft Edge team added warning messages in the Console when a tracker is blocked.

Messages in the Console when tracking prevention blocks access to storage for a tracker

Read more about tracking prevention and the balance between privacy and web compatibility.

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Announcements from the Chromium project

The following sections announce additional features available in Microsoft Edge 80 that were contributed to the open source Chromium project.

Support for let and class redeclarations in the Console

The Console now supports redeclarations of let and class statements. The inability to redeclare was a common annoyance for web developers who use the Console to experiment with new JavaScript code.

Warning

Redeclaring a let or class statement in a script outside of the Console or within a single Console input still causes a SyntaxError.

For example, previously, when re-declaring a local variable with let, the Console threw an error:

The Console in Microsoft Edge 79 showing that the let redeclaration fails

Now, the Console allows the redeclaration:

The Console in Microsoft Edge 80 showing that the let redeclaration succeeds

Chromium issue #1004193

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Improved WebAssembly debugging

DevTools has started to support the DWARF Debugging Standard, which means increased support for stepping over code, setting breakpoints, and resolving stack traces in your source languages within DevTools.

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Network panel updates

Request Initiator Chains in the Initiator panel

You can now view the initiators and dependencies of a network request as a nested list. This may help you understand why a resource was requested, or what network activity a certain resource (such as a script) caused.

A Request Initiator Chain in the Initiator panel

After logging network activity in the Network panel, select a resource and then go to the Initiator panel to view the Request Initiator Chain:

  • The inspected resource is bold. In the screenshot above, ai.2.min.js is the inspected resource.
  • The resources above the inspected resource are the initiators. In the screenshot above, https://www.microsoftedgeinsider.com is the initiator of ai.2.min.js. In other words, https://www.microsoftedgeinsider.com caused the network request for ai.2.min.js.
  • The resources below the inspected resource are the dependencies. In the screenshot above, https://dc.services.visualstudio.com/v2/track is a dependency of ai.2.min.js. In other words, ai.2.min.js caused the network request for https://dc.services.visualstudio.com/v2/track.

Initiator and dependency information can also be accessed by holding Shift and then hovering over network resources. See Display initiators and dependencies in Network features reference.

Chromium issue #842488

Highlight the selected network request in the Overview

After you select a network resource in order to inspect it, the Network panel now puts a blue border around that resource in the Overview. This can help you detect if the network request is happening earlier or later than expected.

The Overview pane highlighting the inspected resource

Chromium issue #988253

See Hide the Overview pane in Network features reference.

URL and path columns in the Network panel

Use the new Path and URL columns in the Network tool to display the absolute path or full URL of each network resource.

The new Path and URL columns in the Network panel

To display the new columns, right-click the Waterfall table header, and then select Path or URL.

Chromium issue #993366

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Updated User-Agent strings

DevTools supports setting a custom User-Agent string through the Network Conditions panel. The User-Agent string affects the User-Agent HTTP header attached to network resources, and also the value of navigator.userAgent.

The predefined User-Agent strings have been updated to reflect modern browser versions.

The User Agent menu in the Network Conditions panel

To access Network Conditions, open the Command Menu and run the Show Network Conditions command.

Chromium issue #1029031

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Audits panel updates

In a later release, the Audits panel was renamed as the Lighthouse panel.

New configuration UI

The configuration UI has a new, responsive design, and the throttling configuration options have been simplified. For more information on the throttling UI changes, see Audits Panel Throttling.

The new configuration UI

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Coverage tool updates

Per-function or per-block coverage modes

The Coverage tool has a new dropdown menu that lets you specify whether code coverage data should be collected per function or per block. Per block coverage is more detailed but also far more expensive to collect. DevTools uses per function coverage by default now.

Caution

You may notice large code coverage differences in HTML files depending on whether you use per function or per block mode. When using per function mode, inline scripts in HTML files are treated as functions. If the script runs at all, DevTools marks the entire script as used code. If the script doesn't run at all, DevTools marks the script as unused code.

The coverage mode dropdown menu

Coverage must now be initiated by a page refresh

Toggling code coverage without a page refresh has been removed because the coverage data was unreliable. For example, a function may be reported as unused if the runtime was a long time ago and the V8 garbage collector has cleaned it up.

Chromium issue #1004203

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Note

Portions of this page are modifications based on work created and shared by Google and used according to terms described in the Creative Commons Attribution 4.0 International License. The original page is found here and is authored by Kayce Basques (Technical Writer, Chrome DevTools & Lighthouse).

Creative Commons License This work is licensed under a Creative Commons Attribution 4.0 International License.