To obtain a chatlog, run the /chatlog command in WoW. The next time you log out, a file called WoWChatLog.txt will be placed in the Logs directory of your World of Warcraft directory (for example, this will be C:\Program Files\World of Warcraft\Logs\WoWChatLog.txt on many computers). This tool will allow you to parse this chat log; simply paste the relevant text below and select the channels and output format you'd like.
Paste the original chat log here:
Include the following channels in the output:
Include Timestamps
Plain Text PHPBB Markup HTML (styles included) HTML (use your own stylesheet)
(This may take a few seconds on longer chatlogs.)