Planned
Last Updated: 05 May 2025 07:31 by ADMIN
Tim
Created on: 02 May 2025 00:17
Type: Feature Request
0
Bring back the Custom Rules Engine

The current Fiddler Everywhere rules do not allow you to simulate modem like you could do with Fiddler Classic. 

https://www.telerik.com/forums/can-fiddler-be-used-to-throttle-an-android%27s-or-iphone%27s-network-connections

I want this functionality brought back so I can do things like we had in the old Fiddler:

Fiddler includes a Custom Rules Engine that can simulate throttling. To enable it go to Rules -> Customize Rules... or (CTRL + R) and set the m_SimulateModem variable to true

The script that executes when this is true is as follows:

if (m_SimulateModem) {
    // Delay sends by 300ms per KB uploaded.
    oSession["request-trickle-delay"] = "300"; 
    // Delay receives by 150ms per KB downloaded.
    oSession["response-trickle-delay"] = "150"; 
}

 

I have tried Delay Request but it's not the same:

 

3 comments
ADMIN
Nick Iliev
Posted on: 05 May 2025 07:31

Hello Tim,

 

When using the Delay action through a rule in Fiddler Everywhere, it will add a delay for each request it matches. What will be matched depends entirely on your matching conditions.

For example, the following rule will delay with 1s (and mark) all sessions because the matching condition is set to match all.

 

 

Regards,
Nick Iliev
Progress Telerik

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Tim
Posted on: 03 May 2025 02:09

I will some additional testing. 

I did not see my upload speeds dropping much when applying a 300ms delay.

Does it operate "per KB" uploaded as the comment mentioned?

Delay sends by 300ms per KB uploaded.

ADMIN
Nick Iliev
Posted on: 02 May 2025 06:21

Hello Tim,

 

Thank you for your feedback! Adding the scripting functionality in Fiddler Everywhere is one of the features highlighted in our roadmap.

The team is already actively researching the best options for adding scraping, but I cannot yet provide a specific timeline for when the feature will be officially available.

That said, the screenshot delay option in Rules should result in the same outcome as using FiddlerScript and the request-trickle-delay session flag. Could you please elaborate on the difference that you are observing and how both are working differently in your case?

 

Regards,
Nick Iliev
Progress Telerik

Love the Telerik and Kendo UI products and believe more people should try them? Invite a fellow developer to become a Progress customer and each of you can get a $50 Amazon gift voucher.