Translation guide
The English word 'viral' has two main uses: describing something related to viruses (medical/biological) and describing content that spreads rapidly online. This guide covers both meanings with natural Japanese expressions.
Describing something caused by or relating to a virus, such as an infection or disease.
The most common and direct translation for 'viral' in medical contexts. It means 'viral' as in 'caused by a virus'.
ウイルス性の感染症が流行しています。
A viral infection is going around.
Literally 'caused by a virus'. Used when you want to emphasize the cause.
Describing content such as videos, posts, or memes that become very popular and spread quickly on the internet.
The loanword 'viral' is widely understood in Japanese internet culture. Often used in compounds like バイラル動画 (viral video).
その動画はバイラルになった。
That video went viral.
ウイルス性 (virus-sei) only means 'viral' in the medical sense. Using it for internet memes will cause confusion. Use バイラル or 急速に広まる instead.
❌ その動画はウイルス性です。
That video is viral. (incorrect, sounds like it's about a virus)
バイラル is a neutral loanword, while バズる is slangy and implies a more explosive, buzz-like spread. バズる is often used for short-lived trends, whereas バイラル can be used for any viral content.
その動画は一晩でバイラルになった。
The video went viral overnight.
バイラルマーケティングは効果的だ。
Viral marketing is effective.
彼はウイルス性の感染症にかかっている。
He has a viral infection.
この病気はウイルスによるものです。
This illness is viral (caused by a virus).
Simply 'of a virus'. Can be used attributively, but ウイルス性 is more common for 'viral'.
ウイルスの遺伝子を調べる。
Examine the viral genes.
Means 'spread rapidly'. A natural way to describe something going viral without using the loanword.
そのツイートは急速に広まった。
That tweet went viral.
Literally 'become a topic'. Implies something is being talked about widely, often used for viral trends.
彼の投稿が話題になっている。
His post is going viral.
Slang derived from 'buzz', meaning to go viral or create a buzz online. Very casual.
この動画、バズってるね。
This video is going viral, huh.
Means 'be spread/disseminated'. Often used in news contexts for information spreading rapidly.
誤情報がSNSで拡散された。
Misinformation went viral on social media.