Translation guide
The most common way to say 'e-book' in Japanese is 電子書籍 (denshi shoseki), a formal term used in publishing and retail. In casual conversation, people often just say 電子書籍 or use the English loanword イーブック (ībukku), though the latter is less common. For specific devices, 電子書籍リーダー (denshi shoseki rīdā) or 電子ブックリーダー (denshi bukku rīdā) are used.
Referring to an electronic book as a publication or content, not the device.
Standard term for e-books in formal and technical contexts. Widely understood.
最近、電子書籍をよく買います。
Lately, I often buy e-books.
この小説は電子書籍でも読めます。
You can read this novel as an e-book too.
Loanword from English. Used in casual contexts or in branding, but less common than 電子書籍.
イーブックで読んだ方が安いよ。
It's cheaper to read it as an e-book.
Less common variant, sometimes used in product names or older contexts.
電子ブックのフォーマットについて教えてください。
Please tell me about e-book formats.
Referring to the physical device used to read e-books.
Standard term for an e-reader device like Kindle or Kobo.
新しい電子書籍リーダーを買いました。
I bought a new e-book reader.
Shortened loanword, sometimes used in tech contexts.
イーリーダーを持ち歩いています。
I carry an e-reader with me.
電子書籍 is the safe, standard choice in most situations. イーブック is understood but may sound like a brand name or overly casual in formal writing.
Alternative term, also common.
電子ブックリーダーは目に優しいです。
E-book readers are easy on the eyes.