Each Session captured by Fiddler Everywhere has multiple attributes ordered in columns. Use these to identify HTTP related issues, to track and debug your site performance, and to leave custom comments.
An auto-generated identification number for the currently listed sessions.
Indicates the HTTP status code from the response. A server issues the status codes in response to a client's request made to the server and represented by a three-digit number. The first digit of the status code specifies one of five standard classes of responses.
- 1xx informational response – the request was received, continuing process
- 2xx successful – the request was successfully received, understood, and accepted
- 3xx redirection – further action needs to be taken to complete the request
- 4xx client error – the request contains bad syntax or cannot be fulfilled
- 5xx server error – the server failed to fulfill a valid request
Full list of all response status code is available at the HTTP/1.1 status code definition article
Indicates the used protocol, which can be HTTP (Hypertext Transfer Protocol) or HTTPS (secure HTTP). The HTTPS is HTTP but with an added secure layer, which is usually TLS (or SSL). The secure layer encrypts the standard HTTP requests and responses, making them far more reliable than the plain-text HTTP. Fiddler can decore the encrypted content, but for this to happen, you must install a trust root certificate. Once the trust certificate is installed and the HTTPS capturing is enabled, Fiddler is effectively a "man-in-the-middle" and can now decode encrypted sessions by switching on the Decode button.
The hostname and the port of the server to which the request was sent.
The URL path, file, and query string from the request.
The HTTP method used by the request (GET, POST, etc.). The HTTP methods are used to set the desired action that needs to be applied to a given resource.
- GET: The GET method requests a representation of the specified resource. Requests using GET should only retrieve data.
- HEAD: The HEAD method asks for a response identical to that of a GET request, but without the response body.
- POST: The POST method is used to submit an entity to the specified resource, often causing a change in state or side effects on the server.
- PUT: The PUT method replaces all current representations of the target resource with the request payload.
- DELETE: The DELETE method deletes the specified resource.
- CONNECT: The CONNECT method establishes a tunnel to the server identified by the target resource.
- OPTIONS: The OPTIONS method is used to describe the communication options for the target resource.
- TRACE: The TRACE method performs a message loop-back test along the path to the target resource.
- PATCH: The PATCH method is used to apply partial modifications to a resource.
Shows the number of bytes in the response body.
Values (if any) from Cache-Control and Expires headers. In case, where both headers are present, the column will display first the values from Cache-Control and then the values for Expires header (separated by semicolon).
The Cache-Control header is containing instructions for caching (for both requests and responses). An example of standard Cache-Control header:
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
The Expires header contains the date/time after which the response is considered invalid. When the Expires header has invalid date value (for example, 0 or -1) that means that the expiration date is in the past, and the resource is already considered expired. An example for standard Expires header:
Expires: Fri, 20 Apr 2020 19:00:00 GMT
In case, where a Cache-Control header with max-age or s-maxage is set, then the value from Expires will be ignored.
The Content-Type header from the response.
The Content-Type header is an indication of the media type of the resource. It is used with requests of type POST and PUT where the client indicates to the server the type of data that is sent. The Content-Type header supports three directives (media-type, charset and boundary) which values are separated in the column by a semicolon.
An example for Content-Type header:
The are many different media-types values which can be used to explicitly set the type of the passed resource. See the list of the common ones here.
The local OS process from which the traffic originated. Examples for Process values:
Process: chrome:54000 Process: outlook: 12564 Process: teams:18352
A field for showing the custom comment.
This column will have a value only if the comment was added previously (for example, when looking into a list of shared sessions with already added comments) or when you explicitly add a comment (via Comment in the context menu).