How do you use web developer tools to monitor and analyze network requests and responses?

1 Accessing the network panel

To access the network panel, you need to open devtools in your browser. The exact method may vary depending on your browser, but usually you can use a keyboard shortcut, such as Ctrl+Shift+I on Windows or Command+Option+I on Mac, or right-click on any element on the web page and select Inspect or Inspect Element. Once devtools are open, you can switch to the network panel by clicking on the Network tab. The network panel will show you a list of all the network requests that are made by the web page, as well as their status, type, size, and time.

2 Filtering and sorting network requests

The network panel allows you to filter and sort network requests based on various criteria, such as name, domain, type, status, size, or time. You can use the filter bar at the top of the panel to enter a text or a regular expression that matches the requests you want to see. For example, you can enter .css to see only CSS files, or 404 to see only requests that failed. You can also use the buttons below the filter bar to filter by type, such as XHR, JS, or Img. To sort network requests, you can click on any column header, such as Name, Status, or Time. You can also drag and drop columns to rearrange them.

3 Viewing request and response details

The network panel also allows you to view the details of each network request and response, such as headers, cookies, parameters, response body, and timing. To view the details, you can click on any request in the list, and a new panel will open on the right side. The new panel will have different tabs, depending on the type and content of the request and response. For example, you can see the Headers tab to view the request and response headers, such as method, URL, status code, content type, and cache control. You can see the Cookies tab to view the request and response cookies, such as name, value, domain, and path. You can see the Params tab to view the query string or form data parameters, such as name and value. You can see the Response tab to view the response body, either as text, JSON, HTML, or image. You can see the Timing tab to view the timing breakdown of the request and response, such as queueing, DNS lookup, connection, request, response, and download.

4 Measuring network performance

The network panel also allows you to measure the network performance of your web page, such as the total number of requests, the total size of requests and responses, and the total load time. You can see these metrics at the bottom of the panel, or hover over any request to see its individual size and time. You can also use the toolbar at the top of the panel to perform various actions, such as reloading the page, clearing the network log, recording or stopping network activity, throttling the network speed, or exporting the network data. You can also use the waterfall view to see how each request affects the page load time, or use the performance panel to see a more comprehensive analysis of your page performance.

5 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?