How to say "certified" in Japanese

• 極め付ききわめつきCommon
  no-adjectiveCovers 'certified' as genuine or valuable: an authoritative verdict that something is the real thing or of proven worth, as with an article whose authenticity is vouched for.
• 保証付きほしょうつきCommon
  no-adjectiveMatches 'certified' only in its guarantee sense: something is offered with a warranty or guarantee attached, so the idea is assurance of quality, not authentication of genuineness.
  この時計とけいは、一いち年間ねんかんの保証ほしょう付ふです。↗

  They guarantee this clock for a year.

Choose 「極め付き」 when 'certified' means authenticated as genuine or valuable — a hallmark of authenticity — and 「保証付き」 when it means guaranteed, with a warranty or promise of quality attached.

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

• 極め付ききわめつきcertified (as genuine, valuable, etc.)
• 保証付きほしょうつきguaranteed
• 極めつけきわめつけcertified (as genuine, valuable, etc.)
• 折り紙付きおりがみつきguaranteed