While is a commonly cited site for free streaming among fans, I recommend using licensed platforms like HIDIVE or Amazon Prime Video to ensure the best viewing quality and support the creators.
There are two "Episode 12" options depending on which season you are watching: Watch Clannad | Prime Video - Amazon.com Watch Clannad | Prime Video. Amazon.com Old school anime style in 2000s - Facebook Watch Clannad Episode 12 for free on gogoanime
Clannad consists of two primary seasons: the original Clannad and its sequel, Clannad ~After Story~ . Episode 12 Breakdown While is a commonly cited site for free