Options Mini Menu
Besides toggling the activation of the panel the Options Mini Menu offers an option for disabling the browser cache and for showing the paint events of a page.
Break On XHR
Clicking the "Break On XHR" button enables a listener for XMLHttpRequests. If an XHR is made then, the debugger stops the script execution immediately and jumps to the Script Panel.
Removes all entries of the list of requests.
When this option is enabled, the entries of the requests list are not deleted when reloading the page. Instead the are grouped by page request, which means, when reloading the page several times you will get several request trees having the page title as root.
You have the possibility to search inside the different requests. Thereby besides the general options for case sensitivity and regular expression search you can optionally also search inside the request bodies.
The main part of the Net Panel is the Request List. When the Net Panel is activated and a page is loaded it starts filling with all HTTP requests made by a page. Each entry displays basic info about the request and a graphical Timeline that depicts load phases in time. The following is a list of information, that is displayed for each request:
- HTTP request method
- HTTP response code and description
- Requested file name (shortened; hovering it shows the entire URL)
- Domain name from where the response came from
- Size of the response
- Graphical Timeline and load time info
Request & Response Details
Every request entry can be expanded by clicking on the left hand twisty in order to see additional info. It's important to note that the entry actually represents both: the request sent to the server and also the response coming back. No matter if it comes from the server or the browser cache, one request-response round-trip is represented by one entry in the list. There are several tabs shown for each request. Depending on the request method and requested file type there are additional tabs with further information. Here's a list of the tabs shown for the different requests:
|Headers||-||Lists the request and response headers of the current request|
|Response||-||Displays the contents of the response unformatted (as they came from the server)|
|Params||GET request||Displays the URL parameters|
|Post||POST request||Displays the POST parameters incl. the source|
|HTML||HTML files||Displays the rendered HTML output|
|JSON||JSON files||Displays the JSON data in a formatted tree structure similar to the DOM Panel|
|XML||XML files||Displays the XML data in a formatted tree structure similar to the HTML Panel|
|Cache||Cached files||Lists cache information to the current request|
|Last Modified||Last time the cache entry was modified|
|Last Fetched||Last time the cache entry was accessed|
|Expires||Expiration time of the cache entry|
|Data Size||Cache entry data size|
|Fetch Count||Number of times the cache entry has been accessed|
|Device||ID for the device that stores this cache entry|
|DNS Lookup||DNS resolution time|
|Connection||Elapsed time required to create a TCP connection|
|Queuing||Time spent in a browser queue waiting for a network connection|
|Waiting||Waiting for a response from the server|
|Receiving||Time required to read the entire response from the server (and/or time required to read from cache)|
|'DOMContentLoaded' (event)||Point in time when DOMContentLoaded event was fired (since the beginning of the request, can be negative if the request has been started after the event)|
|'load' (event)||Point in time when the page load event was fired (since the beginning of the request, can be negative if the request has been started after the event)|
Waterfall Graph Time Extent
In order to keep the X axis (time) in sensible extent, the waterfall graph breaks the time and starts displaying new requests that start later (in the page life) again from the beginning. In other words, a request, that starts after a predefined period of time (1s by default) since the previous request finished, starts from 0 time of the graph again. This avoids endless extension of the X axis, which would make the graph less readable. There is a preference extensions.firebug.netPhaseInterval allowing you to set the gap in milliseconds, after which the time break should happen. If set to 0, breaking doesn't happen at all.
If you right-click on a request, the context menu offers you several options to copy data to the clipboard including the location, the request headers, the response headers and the response body (except for binary files). Furthermore you can open the request in a new tab (which keeps the request method) or open the response in a new tab. For CSS files you even have the possibility to open the file in the CSS Panel or inspect it inside the DOM Panel.