Journaler
Journaler is a noun that refers to a person who keeps a journal or diary. In contemporary English usage, the term is uncommon; most people who write diaries are described as diarists, diary-keepers, or journal writers. Journaler can be formed by adding the agent suffix -er to journal, but its use is largely stylistic or historical rather than standard practice.
Origins and usage: The word follows a common pattern in English for forming agent nouns, but it
Distinctions and related terms: A diarist is someone who regularly records personal experiences, thoughts, and events
In use today: If clarity is required, avoid journaler and opt for diarist, diary keeper, or journal