Network features reference

This article is an outline of the various features of the Network tool, which is used for network analysis and inspecting network activity for a webpage.

See also Inspect network activity, which is a step-by-step tutorial walkthrough of the Network tool.

Record network requests

By default, DevTools records all network requests in the Network tool, so long as DevTools is open.

Stop recording network requests

To stop recording requests:

1. On the Network tool, click Stop recording network log (). It turns grey to indicate that DevTools is no longer recording requests.

2. Press Ctrl+E (Windows, Linux) or Command+E (macOS) while the Network tool is in focus.

Clear requests

Click the Clear () button on the Network tool to clear all requests from the Requests table.

Save requests across page loads

To save requests across page loads, on the Network tool, select the Preserve log checkbox:

DevTools saves all requests until you disable Preserve log.

Capture screenshots during page load

You can capture screenshots to analyze what's displayed for users while waiting for your page to load.

To enable screenshots:

1. In DevTools, open the Network tool.

2. In the upper right within the Network tool, click the Network settings (gear) icon. A row of checkboxes appears.

3. Select the Capture screenshots checkbox:

To capture a screenshot:

1. While the Network tool has focus, press Ctrl+F5 refresh the page. Screenshot are captured and thumbnails are shown below the row of checkboxes.

   You can interact with the screenshots as follows.

2. Hover over a screenshot to display the point at which that screenshot was captured. A yellow vertical line is displayed on the Overview chart pane.

   

3. Click the thumbnail of a screenshot to filter out any requests that occurred after the screenshot was captured.

4. Double-click a screenshot thumbnail to zoom-in and view the screenshot.

5. Press Esc to close the screenshot viewer.

Change loading behavior

Emulate a first-time visitor by disabling the browser cache

To emulate how a first-time user experiences your site, turn on the Disable cache checkbox. DevTools disables the browser cache. This feature more accurately emulates a first-time user's experience, because requests are served from the browser cache on repeat visits.

The Disable Cache checkbox:

Disable the browser cache from the Network Conditions drawer

If you want to disable the cache while working in other DevTools panels, use the Network Conditions drawer:

1. Open the Network Conditions drawer.

2. Select or clear the Disable cache checkbox.

Manually clear the browser cache

To manually clear the browser cache at any time, right-click anywhere in the Requests table, and then click Clear Browser Cache.

Selecting Clear Browser Cache:

Emulate offline

A new class of web apps, named Progressive Web Apps, functions offline with the help of service workers. You may find it useful to quickly simulate a device that has no data connection, when you are building this type of app.

To simulate an offline network experience, select the No throttling dropdown menu > Presets > Offline.

The Offline dropdown menu:

Emulate slow network connections

Emulate Slow 3G, Fast 3G, and other connection speeds from the No throttling dropdown menu.

The Throttling dropdown menu:

You can choose from different presets, such as Slow 3G or Fast 3G. To add your own custom presets, open the Throttling menu, and select Custom > Add.

DevTools displays a warning icon next to the Network tool to remind you that throttling is enabled.

See also Simulate a slower network connection in Inspect network activity.

Emulate slow network connections from the Network Conditions drawer

If you want to throttle the network connection while working in other DevTools panels, use the Network Conditions drawer tool:

1. Open the Network Conditions drawer.

2. Select your connection speed from the Throttling menu.

Manually clear browser cookies

To manually clear browser cookies at any time, right-click anywhere in the Requests table, and then select Clear Browser Cookies.

Override the user agent

To manually override the user agent:

1. Open the Network Conditions drawer tool.

2. Clear the Select automatically checkbox.

3. Select a user agent option from the menu, or enter a custom user agent in the text box.

Set user agent client hints

If your site employs user agent client hints, use the Network conditions panel to provide different user agent client hints.

1. Right-click the webpage and select Inspect.

2. Select Network > Network conditions.

3. In the User agent panel clear the Use browser default checkbox, then select User agent client hints.

   

4. Accept the default value of Custom..., or select a predefined browser and device from the dropdown list.

5. For either choice, set User agent client hints as follows:

   • Brand and Version such as Edge and 92. Click + Add Brand to add multiple brand and version pairs.
   • Full Browser Version such as 92.0.1111.0.
   • Platform and Version such as Windows and 10.0.
   • Architecture such as x86.
   • Device model such as Galaxy Nexus.

   Note

   Set or change any of the user agent client hints. There are no required values.

6. Select Update.

7. To verify changes, click Console and type navigator.userAgentData. Expand the results as needed to view changes to user agent data.

You can also set user agent client hints in Emulate mobile devices (Device Emulation).

Filter requests

You can filter requests by properties, by type, or by time, and you can hide data URLs.

Filter requests by properties

Use the Filter text box to filter requests by properties, such as the domain or size of the request.

If the text box isn't displayed, the Filters pane is probably hidden. For more information, see Hide the Filters pane.

The Filter text box:

You can use multiple properties simultaneously by separating each property with a space. For example, mime-type:image/png larger-than:1K displays all PNGs that are larger than 1 kilobyte. The multi-property filters are equivalent to AND operations. OR operations are currently not supported.

The complete list of supported properties:

Property	Details
domain	Only display resources from the specified domain. You can use a wildcard character (*) to include multiple domains. For example, *.com displays resources from all domain names ending in .com. DevTools populates the autocomplete dropdown menu with all of the domains that are found.
has-response-header	Displays the resources that contain the specified HTTP response header. DevTools populates the autocomplete dropdown menu with all of the response headers that are found.
is	Use is:running to find WebSocket resources.
larger-than	Displays resources that are larger than the specified size, in bytes. Setting a value of 1000 is equivalent to setting a value of 1k.
method	Displays resources that were retrieved over a specified HTTP method type. DevTools populates the dropdown menu with all of the HTTP methods that are found.
mime-type	Displays resources of a specified MIME type. DevTools populates the dropdown menu with all MIME types that are found.
mixed-content	Show all mixed content resources (mixed-content:all) or just the ones that are currently displayed (mixed-content:displayed).
scheme	Displays resources retrieved over unprotected HTTP (scheme:http) or protected HTTPS (scheme:https).
set-cookie-domain	Displays resources that have a Set-Cookie header with a Domain attribute that matches the specified value. DevTools populate the autocomplete with all of the cookie domains that are found.
set-cookie-name	Displays resources that have a Set-Cookie header with a name that matches the specified value. DevTools populate the autocomplete with all of the cookie names that are found.
set-cookie-value	Displays resources that have a Set-Cookie header with a value that matches the specified value. DevTools populate the autocomplete with all of the cookie values that are found.
status-code	Displays resources that match the specific HTTP status code. DevTools populates the autocomplete dropdown menu with all of the status codes that are found.

Filter requests by type

To filter requests by request type, click the buttons on the Network panel:

• XHR
• JS
• CSS
• Img
• Media
• Font
• Doc
• WS - WebSocket.
• Manifest
• Other - Any other type not listed here.

If the buttons don't appear, the Filters pane might be hidden. See Hide the Filters pane.

To enable multiple type filters simultaneously, press and hold Ctrl (Windows, Linux) or Command (macOS) and then click the filters.

Use the Type filters to display JS, CSS, and Document resources:

Filter requests by time

Click and drag left or right on the Overview pane to only display requests that were active during that time frame. The filter is inclusive. Any request that was active during the highlighted time is shown.

Filtering out any requests that were inactive around 300 ms:

Hide data URLs

Data URLs are small files embedded into other documents. Any request that displays in the Requests table that starts with data: is a data URL.

To hide the requests, turn off the Hide data URLs checkbox:

Sort requests

By default, the requests in the Requests table are sorted by initiation time, but you can sort the table using other criteria.

Sort by column

Click the header of any column in the Requests to sort requests by that column.

Sort by activity phase

To change how the Waterfall sorts requests:

• Right-click the header of the Requests table, hover over Waterfall, and then select one of the following options:

  • Start Time - The first request that was initiated is placed at the top.

  • Response Time - The first request that started downloading is placed at the top.

  • End Time - The first request that finished is placed at the top.

  • Total Duration - The request with the shortest connection settings and request or response is placed at the top.

  • Latency - The request that waited the shortest time for a response is placed at the top.

These descriptions assume that each respective option is ranked from shortest to longest. Click the header of the Waterfall column to reverse the order.

The following shows sorting the Waterfall by total duration. The lighter portion of each bar is time spent waiting and the darker portion is time spent downloading bytes:

Analyze requests

So long as DevTools are open, it logs all requests in the Network tool. Use the Network panel to analyze requests.

Display a log of requests

Use the Requests table to display a log of all requests made while DevTools have been open. To reveal more information about each item, click or hover on requests.

The Requests table displays the following columns by default:

• Name. The filename of, or an identifier for, the resource.
• Status. The HTTP status code.
• Type. The MIME type of the requested resource.
• Initiator. The following objects or processes can initiate requests:
  • Parser. The HTML parser.
  • Redirect. An HTTP redirect.
  • Script. A JavaScript function.
  • Other. Some other process or action, such as navigating to a page via a link or entering a URL in the address bar.
• Size. The combined size of the response headers plus the response body, as delivered by the server.
• Time. The total duration, from the start of the request to the receipt of the final byte in the response.
• Waterfall. A visual breakdown of each request's activity.

Add or remove columns

Right-click the header of the Requests table and select an option to hide or show it. Currently displayed options have checkmarks next to them.

Add custom columns

To add a custom column to the Requests table, right-click the header of the Requests table and then select Response Headers > Manage Header Columns.

Display the timing relationship of requests

Use the Waterfall to display the timing relationships of requests. The default organization of the Waterfall uses the start time of the requests. So, requests that are farther to the left started earlier than the requests that are farther to the right.

To see the different ways that you can sort the Waterfall, go to Sort by activity phase.

The Waterfall column of the Requests pane:

Display a preview of a response body

To display a preview of a response body, use the following steps.

1. Click the URL of the request, under the Name column of the Requests table.
2. Select the Preview tab.

The Preview tab is mostly useful to display images.

Display a response body

To display the response body to a request, use the following steps.

1. Click the URL of the request, under the Name column of the Requests table.
2. Click the Response tab.

Display HTTP headers

To display HTTP header data about a request, use the following steps.

1. Click the URL of the request, under the Name column of the Requests table.

2. Click the Headers tab.

Display HTTP header source

By default, the Headers panel shows header names alphabetically. To display the HTTP header names in the order received, use the following steps.

1. Open the Headers panel for the request that interests you. For more information, see Display HTTP headers.

2. Click view source, next to the Request Header or Response Header section.

Display query string parameters

To display the query string parameters of a URL in a human-readable format, use the following steps.

1. Open the Headers panel for the request that interests you. For more information, see Display HTTP headers.

2. Navigate to the Query String Parameters section.

Display query string parameters source

To display the query string parameter source of a request, use the following steps.

1. Navigate to the Query String Parameters section. For more information, see Display query string parameters.

2. Select view source.

Display URL-encoded query string parameters

To display query string parameters in a human-readable format, but with encodings preserved, use the following steps.

1. Navigate to the Query String Parameters section. For more information, see Display query string parameters.

2. Click view URL encoded.

Display cookies

To display the cookies sent in the HTTP header of a request, use the following steps.

1. Click the URL of the request, under the Name column of the Requests table.
2. Click the Cookies tab.

Display the timing breakdown of a request

To display the timing breakdown of a request, use the following steps.

1. Click the URL of the request, under the Name column of the Requests table.
2. Click the Timing tab.

For a faster way to access the data, see Preview a timing breakdown, in the present article.

For more information about each of the phases that may be displayed in the Timing panel, see Timing breakdown phases explained, in the present article.

The Timing panel:

More information about each of the phases.

For more information about accessing the display, see Display timing breakdown.

Preview a timing breakdown

To display a preview of the timing breakdown of a request, in the Waterfall column of the Requests table, hover on the entry for the request.

Previewing the timing breakdown of a request:

To view the data without hovering, see the top of the present section, Display the timing breakdown of a request.

Timing breakdown phases explained

Each of these phases may appear in the Timing tab:

• Queueing. The browser queues requests when any of the following are true

  • There are higher priority requests.
  • There are already six TCP connections open for this origin, which is the limit. Applies to HTTP/1.0 and HTTP/1.1 only.
  • The browser is briefly allocating space in the disk cache.

• Stalled. The request could be stalled for any of the reasons described in Queueing.

• DNS Lookup. The browser is resolving the IP address for the request.

• Initial connection. The browser is establishing a connection, including TCP handshakes and retries and negotiating a Secure Socket Layer (SSL).

• Proxy negotiation. The browser is negotiating the request with a proxy server.

• Request sent. The request is being sent.

• ServiceWorker Preparation. The browser is starting up the service worker.

• Request to ServiceWorker. The request is being sent to the service worker.

• Waiting (TTFB). The browser is waiting for the first byte of a response. TTFB stands for Time To First Byte. This timing includes one round trip of latency and the time the server took to prepare the response.

• Content Download. The browser is receiving the response.

• Receiving Push. The browser is receiving data for this response via HTTP/2 Server Push.

• Reading Push. The browser is reading the local data that was previously received.

Display initiators and dependencies

To display the initiators and dependencies of a request, hold Shift and hover on the request in the Requests table.

DevTools colors:

• Initiators are shown in green.
• Dependencies are shown in red.

Displaying the initiators and dependencies of a request:

When the Requests table is ordered chronologically, if you hover on a line, the line preceding it displays a green request. The green request is the initiator of the dependency. If another green request is displayed on the line before that, that higher request is the initiator of the initiator. And so on.

Display load events

DevTools displays the timing of the DOMContentLoaded and load events in multiple places on the Network tool. The DOMContentLoaded event is colored blue, and the load event is red.

The locations of the DOMContentLoaded and load events on the Network tool:

Display the total number of requests

The total number of requests is listed in the Summary pane, at the bottom of the Network tool.

Caution

This number only tracks requests that have been logged since DevTools was opened. If other requests occurred before DevTools was opened, those requests aren't counted.

The total number of requests since DevTools were opened

Display the total download size

The total download size of requests is listed in the Summary pane, at the bottom of the Network tool.

Caution

This number only tracks requests that have been logged since DevTools was opened. If other requests occurred before DevTools was opened, the previous requests aren't counted.

The total download size of requests:

To verify how large resources are after the browser uncompresses each item, see display the uncompressed size of a resource.

Display the stack trace that caused a request

After a JavaScript statement requests a resource, hover on the Initiator column to display the stack trace leading up to the request.

The stack trace leading up to a resource request:

Display the uncompressed size of a resource

Turn on the Use large request rows checkbox and then examine the bottom value of the Size column.

The following is an example of uncompressed resources. The compressed size of the jquery-3.3.1.min.js file that was sent over the network was 29.9 KB, whereas the uncompressed size was 84.9 KB:

Export requests data

Save all network requests to a HAR file

To save all network requests to a HAR file:

1. In the Requests table, right-click a request and then select Save as HAR with Content. DevTools saves all requests that have occurred since you opened DevTools to the HAR file. You can't filter requests, and you can't save a single request.

Once you save a HAR file, you can import it back into DevTools for analysis. Drag-and-drop the HAR file into the Requests table.

Selecting Save as HAR with Content:

Copy one or more requests to the clipboard

Under the Name column of the Requests table, right-click a request, hover over Copy, and select one of the following options:

Name	Details
Copy Link Address	Copy the URL of the request to the clipboard.
Copy Response	Copy the response body to the clipboard.
Copy as Fetch
Copy as cURL	Copy the request as a cURL command.
Copy All as Fetch
Copy All as cURL	Copy all requests as a chain of cURL commands.
Copy All as HAR	Copy all requests as HAR data.

Select Copy Response:

Copy formatted response JSON to the clipboard

Select a network request and then navigate to the Headers pane. To copy the JSON value of a response, navigate to Request payload, right-click the JSON response content and then select Copy Value.

Pasting the formatted response JSON in Microsoft Visual Studio Code:

Copy property values from network requests to your clipboard

To copy property values from network requests to your clipboard:

1. Open the Headers pane.

2. Open one of the following header sections.

   • Request payload (JSON)
   • Form Data
   • Query String Parameters
   • Request Headers
   • Response Headers

3. Right-click a value and then select Copy value. You can now paste the value into any editor to review it.

Change the layout of the Network panel

You can expand or collapse sections of the Network tool UI to focus important information.

Hide the Filters pane

By default, DevTools shows the Filters pane. To hide the Filters pane, select Filter ().

Use large request rows

Use large rows when you want more whitespace in your network requests table. Some columns also provide a little more information when using large rows. For example, the bottom value of the Size column is the uncompressed size of a request.

To enable large rows, select the Use large request rows checkbox. An example of large request rows in the Requests pane:

Hide the Overview pane

By default, DevTools displays the Overview pane. To hide the Overview pane, clear the Show Overview checkbox.

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).

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