You can view trace information appended at the end of an ASP.NET page or in the trace viewer. In both cases, the information displayed is the same. ASP.NET organizes the trace information in a series of tables that provide diagnostic information about the request that you are viewing. For information on viewing trace information in a page, see How to: Enable Tracing for an ASP.NET Page. For information on viewing trace information in the trace viewer, see How to: View Trace Information with the Trace Viewer.

Trace Output Sections

Trace information appears in the following order.

Request Details

The Request Details section displays general information about the current request and response.

Value	Description
Session ID	The session identification for the specified request.
Time of Request	The time the request was made.
Request Encoding	The character encoding for the request.
Request Type	The HTTP method used (GET or POST).
Status Code	The status-code value associated with the response. For more information, see RFC 2616 at the World Wide Web Consortium (W3C) Web site.
Response Encoding	The character encoding for the response.

Trace Information

The Trace Information section displays the flow of page-level events. If you have created custom trace messages, the messages are displayed in the Trace Information section also.

Value	Description
Category	The custom trace category specified in a Warn or Write method call, if any.
Message	The custom trace message specified in a Warn or Write method, if any.
From First (s)	The elapsed time in seconds since the first trace message was processed. The first trace message appears at the top of the list.
From Last (s)	The elapsed time in seconds between the processing of the current trace message and the preceding trace message.

Control Tree

The Control Tree section displays information about ASP.NET server controls created in the page.

Value	Description
Control ID	The identification for the control. If you have not specified an ID property for the control, ASP.NET generates an ID using the UniqueID property.
Type	The fully qualified type of the control.
Render Size bytes	The size in bytes of the rendered control (including child controls). This is the size of the actual HTML, XML, or other format that is sent to the browser.
ViewState Size bytes	The size in bytes of the control's view state (excluding child controls). For more information, see ASP.NET State Management.
ControlState Size bytes	The size in bytes of the control's control state (excluding child controls). For more information, see ASP.NET State Management.

Session State

The Session State section displays information about values stored in Session state, if any. For more information, see ASP.NET Session State.

Value	Description
Session Key	The key for data stored in session state, if any.
Type	The fully qualified type of the object that stores the data.
Value	A string representation of the data stored in session state, if any.

Application State

The Application State section displays information about values stored in Session state, if any. For more information, see ASP.NET Application State.

Value	Description
Application Key	The key for data stored in application state, if any.
Type	The fully qualified type of the object that stores the data.
Value	A string representation of the data stored in application state, if any.

Cookies Collection

The Request Cookies and Response Cookies sections display information about the cookies passed between the browser and the server on each request and response. The section displays both persistent and session cookies. ASP.NET creates some cookies automatically, such as those for cookie-based Session state and forms authentication. For more information, see ASP.NET Cookies.

Value	Description
Name	The name of the cookie.
Value	The value of the cookie, or subkeys and values if the cookie is multivalued.
Size	The size in bytes of the cookie.

Headers Collection

The Headers Collection section displays information about request and response message header name/value pairs, which provide information about the message body or requested resource. Header information is used to control how request messages are processed and response messages are created. For more information on HTTP headers, see RFC 2616 at the World Wide Web Consortium (W3C) Web site.

Value	Description
Name	The name of the header.
Value	The value of the header.

Form Collection

The Form Collection section displays name/value pairs that show the form element values (control values) submitted in a request during a POST (postback).

Value	Description
Name	The name of the form variable.
Value	The value of the form variable.

Querystring Collection

The Querystring Collection section shows the values passed in the URL. In a URL, query string information is separated from the path information by a question mark (?); multiple query string elements are separated by an ampersand (&). Query string name/value pairs are separated by an equals sign (=). The QueryString property of the HttpRequest object returns a NameValueCollection of query string variables.

Value	Description
Name	The name of the query string variable.
Value	The value of the query string variable.

Server Variables

The Server Variables section displays a collection of server-related environment variables and request header information. The ServerVariables property of the HttpRequest object returns a NameValueCollection of server variables.

Value	Description
Name	The name of the server variable.
Value	The value of the server variable.