You must be doing something wrong then, because I use it to automate Javascript-heavy websites. Maybe if you showed the code you've been using to "test" this, I could show you your error. Most likely, you've been using repeated calls to ->get, which are akin to pasting an URL into the browser, instead of using ->click() on the appropriate DOM models. But then again, comparing what gets sent over the wire using one method or the other would even allow you to replicate the whole scenario using WWW::Mechanize, and it seems you haven't looked at what gets actually sent to determine the cause of the difference. Use Wireshark or the Mozilla Live HTTP Headers extension to inspect what gets sent to the server by the browser.