Fiddler - add latency on single response without modifying response

Question

In Fiddler how can I slow down the response of a specific request only, while passing through the response from the server?

I'm aware I can simulate a slow speed for all requests - that's not what I want.

Using the AutoResponder with a specific rule forces me to choose what to respond with.

How can I use the "Latency" feature without modifying the response? Is this possible in Fiddler?

Answer 1

I understood your question that you want to delay either request or response time for a specific request.

You could do it with the FiddlerScript module by updating the oSession object.

onBeforeRequest

// Delay sends by 300ms per KB uploaded.
oSession["request-trickle-delay"] = "300"; 

onBeforeResponse

// Delay receives by 150ms per KB downloaded.
oSession["response-trickle-delay"] = "150"; 

You would also need to filter the correct request in the selected method.

Filtering

// Sample Rule: Break requests for URLs containing "/path/"
if (oSession.uriContains("/path/")) {
}

if (oSession.hostname == "some.hostname") {
}

if (oSession.url == "some.url") {
}

Additional info can be found here

Hope it helps

Answer 2

Rather than using the latency feature, you can enter *delay:5000 as the then respond with... command, instead of a file path.

I noticed that the rules are ignored with a blank response, so you can use the latency with a command/path of *action, which isn't a real action, but causes the rule to execute and the latency to take effect, in case you really want to use the Latency column.