HTTP Monitor, Throttling, Reverse Proxy as Web App debugging tool (No that's NOT my new nickname!)

Tech-Weblog by Christoph C. Cemper pointed me to Charles which is Java shareware app ($50 paypay after 10 days) with the the following list o' features:

• Cookies are shown in the HTTP headers, so you can see exactly what cookies you are sending and receiving.


• Every request and response is recorded in Charles. Redirects that are often too quick to see when
  testing with a web browser can be seen in Charles. Requests from applications other than your web browser
  (such as Flash movies) can also be seen.


• Request and response sizes are shown in Charles, so you can see how big each request was.


• Assets loaded from an HTML page are recorded so that you can see how many images etc are loaded by a page, and where from.


• All files can be viewed, including JavaScript files, CSS files, HTML files etc.


• Mirror all responses to disk, recording your session.



• Blacklist sites so that requests are blocked.


• See the results of caching by seeing cached responses (304 Not Modified), and requests containing
  last modified dates (IfModifiedSince).


• Disable caching by removing cache related headers from requests and responses as they pass through Charles,
  ensuring that you are always requesting the latest file.


• See whether a cache has served your request by looking for cache-hit HTTP headers.


• View the encrypted HTTPS communications.



• Reveal unexpected requests, such as typos and 404s.


• View requested images.


• Throttle your web connection to a specified bytes/second speed, and millisecond latency. This
  enables you to simulate modem conditions on a high speed internet connection


• Spoof DNS name to ip mappings so that you can test a domain name before it has gone live. Very useful for testing your virtual hosting.


• Export to CSV all of the summary data captured by Charles for analysis and reporting in Excel



• Reverse proxy creates ports on the localhost that act as regular HTTP servers, but forward all requests to a specified web server.


• SSL debugging enables you to view requests and responses in plain text even when communicating with an SSL secured web server.


• HTTP/1.1 support - understands some HTTP/1.1 specific responses, and forces no keep-alives

I can think of lots of times when I wanted to see just what was going on between the app (or broswer) and the server, and the Throttle could be used to test "What if I only had a dial up line rather that this 10 Terabit Ethernet connection" scenario testing. Lot's of geeky goodness here.