Using Fiddler to Simulate DSL Speeds

Matt F. taught me how to modify Fiddler so that you can simulate DSL speeds:

1. Open Fiddler

2. Select Rules > Customize Rules…

3. CustomRules.js will open in a text editor. Modify the two values below. (Note: to find them quickly, you can search on the word “trickle.”)

Change

// Delay sends by 300ms per KB uploaded.

oSession["request-trickle-delay"] = "300";

To

// Delay sends by 300ms per KB uploaded.

// oSession["request-trickle-delay"] = "300";

// DSL

oSession["request-trickle-delay"] = "75";

Change

// Delay receives by 150ms per KB downloaded.

oSession["response-trickle-delay"] = "150";

To

// Delay receives by 150ms per KB downloaded.

// oSession["response-trickle-delay"] = "150";

// DSL

oSession["response-trickle-delay"] = "38";

4. Save and close custom rules.

You can now switch to DSL speeds in Fiddler by doing the following:

5. Rules > Performance > Simulate Modem Speeds