note: the tutorial below is only viable if you _exclusively_ want to check HTTP proxies 

Out of the box, Charon can be slow at times. That's because it carries lots of features we don't really need to scan and check HTTP proxies.

Using the standard settings, just loading a proxy list can take 30 minutes and more per list because of reverse DNS lookups and stuff. With settings tweaked for HTTP proxy checking, it takes 5 seconds.

Suggested Settings:

General Options

• Resolve proxies to IP upon loading -> disabled!
  No more thousands of DNS queries just for the sake of filtering a few. This speeds up loading a list of proxy servers a lot.

Connect Options

• Threads -> as many as possible!
  A Charon thread, in other words, is "one connection to a proxy server". You want to set this as high as possible. The optimal number of threads depends on your internet connection and your computer. On a broadband connection (ADSL,SDSL,Cable,...) you can easily run 35 threads and more.
  
  Attention, Windows XP users: Windows XP has got an integrated connection limit. On a standard Windows XP installation, you are limited to only 10 threads! To overcome this, there is a patcher application available over at lvllord.de which fixes this limitation.
  
  
  
• Timeout -> 15 seconds or less!
  A proxy is considered dead if the Charon checker process runs into a timeout before it receives a response from the proxy. I mostly use 10-15 seconds. If the proxy is dead, it won't answer even if you raise the timeout. If it is too busy to respond within 15 seconds, it is overloaded and will do more harm than good.
  
  Again, the best setting depends on your internet connection and also your distance to the proxy itself. For example, if you are from Asia and want to check european proxies, you may want to raise this value a bit.
  
  
• Scroll Display Windows -> unchecked! 
  This is more of a cosmetic change, but saves a bit of CPU load.
  
  
• Resolve Proxies to Hostnames -> unchecked!
  If you have a good, IP-based filter list (PlanetLab, etc.), you don't need hostnames unless you are paranoid.
  
  
• Check "Connect" ability -> unchecked!
  For simply HTTP proxies, the "HTTP Connect" method is completely unimportant. Deactivate it!
  
  
• Check Country -> unchecked!
  Only useful if you want to find a proxy from a certain country. Otherwise, disable this.
  
  
• Test Gateway Servers all the way to the end -> unchecked!
  What this option does is test if the current proxy is a gateway to another proxy (which may already be in the list...). For simply HTTP checking, I suggest to deactivate it. On the other hand, you might have a need for a list without gateway proxies.
  
  Bottom Line: If you don't know, what this is, enable it. Otherwise uncheck this option as suggested.
  
  
• Check Proxies for Socks4/5 -> unchecked!
  Off, since we want to check HTTP servers exclusively.
  
  
  

Screenshot: Example of suggested Charon settings according to this tutorial.