Translation guide
Japanese words for 'detergent' depend on what you are cleaning: laundry, dishes, or general household surfaces. The most common everyday word is 洗剤 (せんざい), but specific types have their own names.
A substance used for cleaning, especially laundry or dishes.
The most common and general word for detergent. It covers laundry detergent, dishwashing liquid, and other cleaning agents.
洗剤を買わなくちゃ。
I need to buy detergent.
この洗剤はよく泡立つ。
This detergent lathers well.
Detergent specifically for washing clothes.
Specifically laundry detergent. Often shortened to just 洗剤 in context.
洗濯洗剤が切れた。
We're out of laundry detergent.
Literally 'detergent for laundry use'. More explicit, often seen on product labels.
洗濯用洗剤はどこにありますか？
Where is the laundry detergent?
Detergent for washing dishes by hand or in a dishwasher.
Standard term for dishwashing liquid. Often shortened to 食器洗い洗剤 or just 洗剤.
食器用洗剤をスポンジにつけてください。
Put some dish soap on the sponge.
Kitchen detergent, often used interchangeably with 食器用洗剤.
台所用洗剤がなくなった。
We ran out of kitchen detergent.
Detergent specifically for dishwashers (食洗機).
食洗機用洗剤を買い足さないと。
I need to buy more dishwasher detergent.
Detergent in powder form, often for laundry.
Powdered detergent. Common for laundry.
粉末洗剤は液体より安い。
Powdered detergent is cheaper than liquid.
Detergent in liquid form.
Liquid detergent, used for laundry or dishes.
液体洗剤のほうが溶けやすい。
Liquid detergent dissolves more easily.
In daily conversation, 洗剤 (せんざい) is often enough. Context usually makes it clear whether you mean laundry or dish detergent. If you need to be specific, add 洗濯 (せんたく) or 食器 (しょっき).
石鹸 means 'soap', not detergent. While some cleaning products are soap-based, 洗剤 is the correct word for modern synthetic detergents.