Indicates something is unimportant or not worth worrying about ('inconsequential'; 'not worth caring about').
細かいことはどうでもいいから、全体を見直そう。
Don't worry about the small details; let's review the whole thing.
そんな噂はどうでもいいよ。本当かどうか怪しいし。
That rumor is irrelevant. It's doubtful whether it's true.
成績よりも健康が大事だから、点数はどうでもいいとは言えないが。
Health is more important than grades, so I can't exactly say scores don't matter, but still...
Used to mean 'whatever', 'whichever', or 'I don't care' — expressing indifference (e.g., 'it's all the same to me').
どこのレストランに行く？ — どうでもいいよ、君が決めて。
Which restaurant shall we go to? — Whatever, you decide.
今日は雨でも晴れでもどうでもいい。家にいるつもりだ。
I don't care whether it's rainy or sunny today. I plan to stay home.
あの映画、面白い？ — うーん、どうでもいいかな。
Is that movie interesting? — Hmm, I don't really care.