What's New In DevTools (Chrome 79)
New features for cookies
Debug why a cookie was blocked
After recording network activity, select a network resource and then navigate to the updated Cookies tab to understand why that resource's request or response cookies were blocked. See Changes to the default behavior without SameSite to understand why you might be seeing more blocked cookies in Chrome 76 and later.
- Yellow Request Cookies were not sent over the wire. These are hidden by default. Click show filtered out request cookies to show them.
- Yellow Response Cookies were sent over the wire but not stored.
- Hover over More Information
![info]()
to learn why a cookie was
blocked. - Most of the data in the Request Cookies and Response Cookies tables comes from the resource's HTTP headers. The Domain, Path, and Expires/Max-Age data comes from the Chrome DevTools Protocol.
to learn why a cookie was
blocked.Chromium issues #856777, #993843
View cookie values
Click a row in the Cookies pane to view the value of that cookie.
Note: The main difference between the Cookies tab in the Network panel and the Cookies pane in the Application panel is that the Cookies pane in the Application panel lets you edit and delete cookies.
Chromium issue #462370
Simulate different prefers-color-scheme and prefers-reduced-motion preferences
The prefers-color-scheme media query lets you match
your site's style to your user's preferences. For example, if the prefers-color-scheme: dark
media query is true, it means that your user has set their operating system to dark mode and
prefers dark mode UIs.
Open the Command Menu, run the Show Rendering
command, and then set the Emulate CSS media feature prefers-color-scheme dropdown to debug
your prefers-color-scheme: dark and prefers-color-scheme: light styles.
prefers-color-scheme: dark is set (middle box) the Styles pane (right box)
shows the CSS that gets applied when that media query is true and the viewport shows
the dark mode styles (left box).
You can also simulate prefers-reduced-motion: reduce using the Emulate CSS media feature
prefers-reduced-motion dropdown next to the Emulate CSS media feature prefers-color-scheme dropdown.
Chromium issue #1004246
Code coverage updates
The Coverage tab can help you find unused JavaScript and CSS.
The Coverage tab now uses new colors to represent used and unused code. This color combination is proven to be more accessible for people with color vision deficiencies. The red bar on the left represents unused code, and the bluish bar on the right represents used code.
The new URL filter text box lets you filter out patterns of URLs.
The Sources panel now displays code coverage data by default. Clicking the red or bluish marks next to the line number opens the Coverage tab and highlights the file.
Chromium issues #1003671, #1004185
Debug why a network resource was requested
After recording network activity, select a network resource and then navigate to the Initiator tab to understand why the resource was requested. The Request call stack section describes the JavaScript call stack leading up to the network request.
Note: You can also access this data by hovering over the Initiator column in the Network Log. We added the Initiator tab because it's more accessible.
Chromium issues 963183, 842488
Console and Sources panels respect indentation preferences again
For a long time DevTools has had a setting to customize your indentation preference to 2 spaces, 4 spaces, 8 spaces, or tabs. Recently the setting was essentially useless because the Console and Sources panels were ignoring the setting. This bug is now fixed.
Go to Settings > Preferences > Sources > Default Indentation to set your preference.
Chromium issue #977394
New shortcuts for cursor navigation
Press Control+P in the Console or Sources panels to move your cursor to the line above. Press Control+N to move your cursor to the line below.
Chromium issue #983874
Feedback
To discuss the new features and changes in this post, or anything else related to DevTools:
- File definite bug reports and feature requests at Chromium Bugs.
- Discuss possible features, changes, and bugs on the Mailing List.
- Get help on how to use DevTools on Stack Overflow.
- Tweet us at @ChromeDevTools.
- File bugs on this document in the Web Fundamentals repository.
Consider Canary
If you're on Mac or Windows, consider using Chrome Canary as your default development browser. Canary gives you access to the latest DevTools features.
Note: Canary is released as soon as its built, without testing. This means that Canary breaks about once-a-month. It's usually fixed within a day. You can go back to using Chrome Stable while Canary is broken.
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