You can stream "Whose Line Is It Anyway?" on several platforms:

• The current revival series hosted by Aisha Tyler is available on The CW's official site and streaming service

• The original Drew Carey-hosted episodes can be streamed on Amazon Prime Video, including Amazon Prime Video with Ads

• The Roku Channel and Pluto TV also offer the show for free with ads

• HBO Max is another platform that has the Drew Carey episodes available

Additionally, some episodes and clips are available unofficially on YouTube and other video-sharing sites, but for official streaming, the above platforms are the main options.