Simulate Slow Internet Connection while Testing your Apps

So you have your Next-gen cool Web 2.0 application ready! You have tested it on your LAN environment and on your high speed internet connection – all seems ok and you are ready to deploy it in the ‘real world’. A few hours later, you get feedback that your application does not perform well on slower connections. That hurts!

Well the truth is that real world internet connections are much slower than you think. Your application end users may not always be broadband users but also people accessing your app through a dial-up connection, mobile sets, 3G or USB dongles. Most designers and developers forget to test their application on slower internet connections, resulting in a poor performing application.

Now there are many tools that let you simulate slow network connections. Out of them, what caught my attention is a nice Firefox browser plug-in that ‘effortlessly’ lets you simulate different speeds of Internet connection and lets you view the effects of slow speeds on your application. The plug-in is called Firefox Throttle.

Firefox Throttle is an extension that allows you to control download/upload rates and monitor current bandwidth utilization. Amongst other features, what I liked the most was that it lets you throttle localhost connections as well. Cool! Here’s a screenshot of the plugin in action.


The plug-in shows the current bandwidth utilization indicators in its Status panel as shown below and lets you quickly turn on/off throttling.


You may also want to check out Sloppy

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About The Author

Suprotim Agarwal
Suprotim Agarwal, ASP.NET Architecture MVP (Microsoft Most Valuable Professional) works as an Architect Consultant and provides consultancy on how to design and develop Web applications.

Suprotim is also the founder and primary contributor to DevCurry, DotNetCurry and SQLServerCurry. He is the Editor of a Developer Magazine called DNC Magazine. He has also written two EBooks 51 Recipes using jQuery with ASP.NET Controls. and The Absolutely Awesome jQuery CookBook

Follow him on twitter @suprotimagarwal


Nello said...

Thanks for this! I'm right in the middle of exactly this situation.

Capecy said...

I wanted to tell you that me love this mix of topics on your blog--You rock dude!

Ultimate Privacy said...

Oh wow that makes a lot of sense dude.


Anonymous said...

Unfortunately, this is a windows only plug in.

Brad said...

Excellent! Exactly what I've been searching for!

Anonymous said...

Look at wanem. It can do even more sophisticated things. You burn it to a CD, drop it in a spare server and reboot. It then acts as a router. As such, it supports any platform that can do tcp/ip.

Anonymous said...

Is there something like this available for linux so that real developers can use it also? ;)

Suprotim Agarwal said...

wanem looks good! Thanks for sharing.

For Linux -

MacOS -

Disclaimer: I have not tried the tools for Linux and MacOS..picked from

Anonymous said...

"Real" developers aren't doing web apps.

madth3 said...

Good post and beter comments.

I needed something like this a year ago and the network guys could not help me but I'm sure I will be needing it again.


duncanbeevers said...

Charles Web Proxy provides a nice cross-platform tool for analyzing web traffic and can throttle every HTTP-communicating application on your system, not just Firefox.

For-pay, but an essential tool

Paul J said...

Wow thats great, now I can remember what it was like to be on dial up. lol

But for development yes this is a great tool! :)

Mastermix said...


FlashFiles said...

Great tool, just what i needed, i used Fiddler to simulate modem speed, but with it i couldn't set speed only modem default.

Thanks for sharing

Anonymous said...

i can't find the add-on anymore?!

JessT said...

Incase anyone can't find the add-on:

Anonymous said...

Does not work.

Anonymous said...

Is there a version of Throttle plugin that works with Firefox 18?


enlighten said...

nice article

enlighten said...

Nice article ! Do you want to increase your browser speed , use the following steps :

Uninstall toolbars
Disable toolbars and extensions directly from your browser
Clear browsing cache and cookies
Reset your browser settings

Use the following tips to increase your internet speed :
1. Clear cookies from your browser
2. Close unwanted background tasks when you are working with the internet .
3. Scan your internet by using standard Anti-virus software
4. Reset your modem and reconnect with the internet.After that , you can test your internet speed by using to get better results .