hhhhh or also known as
红红火火恍恍惚惚
(hóng hóng huo huǒ huǎng huǎng hū hū)
This is a common internet slang that you might find while browsing through Chinese Forums or Chinese Weibo or WeChat comments. In Chinese, laughter is usually written as 哈哈哈 and shares the same phonetic sounds as laughter in English (which is Hahaha). This is then abbreviated in Chinese into simply the first letter of each character, hence ‘hhhh’, which is much easier to type. There is no set limit for how many times a user can repeat the letter, e.g. both ‘hhh’ and ‘hhhhhhh’ are acceptable and mean the same thing.
However, when the letter ‘h’ is inputted 8 times into a Chinese writing system, such as Sogou, the system uses predictive text to produce two four-character adjectives, which is: ‘红红火火’ describing wealth and general prosperity, and ‘恍恍惚惚’, meaning confusion and daze. So both 红红火火恍恍惚惚 and hhhh are the Chinese equivalents of LOL (Laugh Out Loud)