NICONICO animation is an online video sharing website provided by NIWANGO, often referred to as niconico or nico for short. Similar to online video sites such as YouTube, NICONICO Animation provides the function for viewers to leave comments on the video, and the comments will appear on the video in the form of subtitles.

In addition, due to factors such as equipment and bandwidth load, NICONICO Animation stipulates that those who watch videos must register, and open users according to the order of registration. 2:00-19:00) to log in, and also provide paid accounts. More than 2 million people have signed up so far.

On December 12, 2006, animation began to provide experimental services called ニコニコ Animation (仮).

At this time, NICONICO Animation just stored videos on YouTube, added the function of instant message subtitles, and did not provide video upload services, and had no formal relationship with YouTube. After February 23, 2007, YouTube banned NICONICO animation from accessing its videos, so NIWANGO launched its own animation sharing service SMILEVIDEO. At present, NICONICO Animation can access animations stored on websites such as SMILEVIDEO and photozou.

The biggest feature of NICONICO animation is the message function in the form of subtitles. Users can freely specify the time when subtitles appear, their position on the video, font size, color, etc. Comments can be moved from the right side of the video to the left side, or can be fixed in a certain position for a period of time.

The vast majority of NICONICO animation users are Japanese, but according to management statistics, about 1% of daily video views come from Taiwan and 0.5% from Hong Kong. This made NICONICO Animation start to provide Taiwan version of services on October 18, 2007, providing traditional Chinese user interface, dedicated message system and NICONICO market.