How to say "bestseller" in Japanese

• ベストセラーJLPT N1approx.Common
  nounThe common, direct word for a bestseller: a book that sells in very large numbers. When you simply mean 'a bestseller', this is the word to reach for.
  この本ほんはかつてはベストセラーだったが、今いまは絶版ぜっぱんになっている。↗

  This book, which was once a best seller, is now out of print.
• ヒット作ヒットさく
  nounA less common word for a work — film, song or book — that is a hit; the 'bestseller' sense is secondary. Use it when the emphasis is a work's success rather than book sales.
• ヒット商品ヒットしょうひん
  nounReally 'hit product': a product that sells extremely well. The 'bestseller' rendering applies within that product sense, so this is seldom the word you want for a best-selling book.

For the plain sense of a best-selling book, 「ベストセラー」 is the default; 「ヒット作」 presents a film, song or book as a hit, and 「ヒット商品」 is for products that sell well rather than for books.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• ベストセラーbestseller
• ヒット作ヒットさくhit (film, song, book, etc.)
• ヒット商品ヒットしょうひんhit product