Translation guide
In Japanese, expressing 'good idea' depends on whether you're complimenting a suggestion, agreeing with a plan, or describing something as well thought-out. The most common expressions are いい考え (ii kangae) and いいアイデア (ii aidea), but natural usage often involves set phrases like いいね (ii ne) or それはいい (sore wa ii).
いいね！
Good idea! (casual agreement)
それはいい考えですね。
That's a good idea.
Reacting positively to someone's idea, proposal, or plan in conversation.
A casual, all-purpose reaction meaning 'That's good' or 'Sounds good.' Often used to agree with a suggestion.
明日映画に行かない？ いいね！
Want to go to a movie tomorrow? Good idea!
Literally 'That is good.' A slightly more explicit way to say 'That's a good idea.' Can be used in both casual and polite contexts.
週末にピクニックに行くのはどう？ それはいいね。
How about going on a picnic this weekend? That's a good idea.
Directly translates to 'That's a good idea.' Natural but slightly more explicit than いいね. The ね softens the statement.
もっと早く出発したほうがいいよ。 いい考えだね。
We should leave earlier. Good idea.
Uses the loanword アイデア. Common in casual speech, especially among younger people or in creative contexts.
新しいアプリを作ろうよ。 いいアイデアだね！
Let's make a new app. Good idea!
Means 'excellent idea' or 'brilliant plan.' Somewhat formal or emphatic. Often used when someone proposes a clever solution.
その問題はこう解決しよう。 名案だ！
Let's solve the problem this way. Brilliant idea!
Stating that a plan, design, or method is clever, effective, or sensible.
The standard way to say 'good idea' as a noun phrase. Can be used in statements like 'That's a good idea' or 'I have a good idea.'
それは良い考えだと思います。
I think that's a good idea.
何か良い考えはありますか？
Do you have any good ideas?
Common alternative using the loanword. Slightly more casual and often used in business or creative settings.
このデザインはとてもいいアイデアですね。
This design is a really good idea.
Means 'a smart way of doing things.' Emphasizes cleverness or efficiency rather than just being 'good.'
その方法は賢いやり方だね。
That method is a smart idea.
Accepting or approving a plan, often in decision-making contexts.
Literally 'That is good.' Used to agree with a specific proposal, meaning 'That's the best option' or 'Let's do that.'
どのレストランにする？ あのイタリアンがいい。 うん、それがいいね。
Which restaurant should we choose? That Italian place is good. Yeah, that's a good idea.
Means 'Let's do that.' A direct way to agree to a suggestion and move to action.
今すぐ始めよう。 そうしよう。
Let's start right now. Good idea, let's do that.
Means 'agreement' or 'I agree.' Often used in meetings or formal discussions to second a motion.
Expressing that an idea is actually bad or foolish, often with a tone of disbelief.
The same phrase can be used sarcastically. Tone of voice and context make the irony clear. Often followed by a rebuttal.
Without clear sarcastic tone, this will be taken as a genuine compliment.
徹夜で全部終わらせよう。 いい考えだね、明日倒れるけど。
Let's pull an all-nighter and finish everything. Good idea, except we'll collapse tomorrow.
考え (kangae) is a native Japanese word meaning 'thought' or 'idea' in a broad sense. アイデア (aidea) is a loanword from English and often implies a more creative, novel, or practical concept. Both are common, but アイデア can sound slightly more modern or business-like. In casual speech, アイデア is very natural for 'good idea' as a reaction.
While 良い考え is correct, in casual conversation it can sound a bit stiff or literal. Japanese speakers often use shorter reactions like いいね or それはいい to express the same sentiment more naturally.
それはいい考えだね。そうしよう。
That's a good idea. Let's do it.
何かいいアイデアある？
Do you have a good idea?
その提案に賛成です。
I agree with that proposal. (That's a good idea.)