Network slowdown proxies

Recently I’ve met a problem: I need to test my web application in extremely low bandwidth conditions (like old modems, GPRS mobile connections and so on). I know there are some tools to simulate that – but as usual, details are missing. So here are my findings – these might be of help for someone.

I’ve found two tools:

• Sloppy
• Charles

The first one is a basic network slowdown proxy which does not require installation, you only need to have Java Web Start installed and you’re done. It offers a limited socket redirection functionality but… it does not seem to support POST requests (or I never figured out why.. Or my Flash application didn’t work with it… Don’t know exactly in fact). And it is free.

The second one, Charles, is actually much more than a network slowdown tool. It is a full HTTP debugging proxy, as author says, and this seems to be true. You can limit bandwidth, monitor and analyze traffic, apply filters – lots of useful stuff. There are only two problems:

• it is not free ($50 single user license)
• it hangs sometimes (not good especially for a non-free application)

But… it works for me (not very reliably, although), so – Charles is my choice for now.