Translation guide
How to express that something is not persuasive, believable, or fails to convince in Japanese.
Describing an argument, excuse, or explanation that lacks credibility or fails to persuade.
The most common and natural way to say something is unconvincing. Literally 'lacks persuasive power'.
彼の説明は説得力がなかった。
His explanation was unconvincing.
その言い訳はまったく説得力がない。
That excuse is completely unconvincing.
Describing acting, pretending, or a performance that fails to be believable.
Directly means 'bad acting'. Used when someone's performance or pretense is not believable.
彼の驚いたふりは演技が下手だった。
His surprised act was unconvincing (bad acting).
Describing something that looks or seems fake, not genuine, or not up to standard.
Means 'to look inferior' or 'pale in comparison'. Can imply something is unconvincing compared to expectations.
本物と比べると見劣りする。
It looks unconvincing compared to the real thing.
説得力がない focuses on the lack of persuasive power in the argument itself. 納得できない focuses on the listener's subjective inability to accept it. Use 説得力がない for objective criticism, 納得できない for personal feelings.
彼の説明は説得力がないが、私は納得した。
His explanation was unconvincing, but I accepted it.
There is no single adjective that directly translates 'unconvincing' in all contexts. Avoid using 非説得的 (hisettokuteki) as it is not natural Japanese. Use the phrases above depending on the situation.
Means 'cannot accept/be convinced'. Focuses on the listener's inability to be persuaded.
彼の主張はどうも納得できない。
His argument is somehow unconvincing.
Idiomatic expression meaning 'doesn't sit right' or 'not fully convincing'. Slightly more subjective and emotional.
彼の話はどうも腑に落ちない。
His story is somehow unconvincing.
Formal term meaning 'low credibility'. Used for evidence, data, or sources rather than everyday arguments.
このデータは信憑性が低い。
This data is unconvincing (lacks credibility).
Means 'forced', 'unnatural', or 'contrived'. Describes behavior that is obviously fake.
彼女の笑顔はわざとらしかった。
Her smile was unconvincing (forced).
Colloquial term meaning 'smells like a lie' or 'obviously fake'. Stronger and more direct.
彼の言い訳は嘘くさい。
His excuse sounds unconvincing (like a lie).
Casual adverb meaning 'not quite' or 'lacking something'. Can describe an unconvincing result or impression.
このデザインはいまいちだね。
This design is a bit unconvincing, isn't it?