How to say "open" in Japanese

• ひらくJLPT N4approx.Common
  godan verb, intransitive verb, transitive verbThe general-purpose verb for opening something shut or folded; it also covers undoing, unsealing and unpacking. Typical when you open a book, or when 'open' really means 'undo' or 'unseal'.
• 開くあくJLPT N5approx.Common
  godan verb, intransitive verbDescribes a door or the like opening — the intransitive partner of 開ける. The opening thing is the subject: use it when the door opens, whether someone opens it or it moves by itself.
  ぐいと押おすとドアは開あいた。↗

  The door yielded to a strong push.
• 開けるあけるJLPT N5approx.Common
  ichidan verb, transitive verbThe transitive counterpart of 開く: someone opens a door or the like, unwraps a parcel or package, or unlocks something. When you open the door yourself, this is the verb you want.
  あなたの手紙てがみを間違まちがってあけてしまってすいませんでした。↗

  I'm sorry I opened your mail by mistake.
• 露骨ろこつJLPT N1approx.Common
  na-adjective, nounCovers only the figurative 'open' meaning unconcealed and undisguised — open hostility, a blatant remark. It carries a negative nuance, and it is never the word for opening a door or anything physical.
  露骨ろこつに嫌いやな顔かおをして、彼かれを睨にらみつけた。↗

  I glared at him with a blatant look of disapproval on my face.
• 公然こうぜんJLPT N1approx.Common
  no-adjective, taru-adjective, adverb (with と)Also figurative 'open': public and overt — done in the open rather than hidden, as with open defiance. Unlike 露骨 it stresses public visibility rather than bluntness, and it never applies to physical opening.
  その国くには公然こうぜんと核武装かくぶそうするとおどしている。↗

  That country has openly threatened to go nuclear.

For a physical opening, choose 「開ける」 when someone opens a door and 「開く」 when it opens; 「ひらく」 covers opening something folded plus undoing, unsealing and unpacking; 露骨 and 公然 serve only the figurative 'open' meaning unconcealed or public.

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

• ひらくto open
• 開くあくto open (e.g. doors)
• 開けるあけるto open (a door, etc.)
• 露骨ろこつopen
• 公然こうぜんopen
• 繰り広げるくりひろげるto unfold
• おおっぴらopen
• 咲くさくto bloom
• 打ち明けるうちあけるto confide
• はだけるto open (e.g. one's robe)
• 開梱かいこんopen (as of a pack)
• あけすけopen
• 営業中えいぎょうちゅうopen (for business)
• 無蓋むがいopen
• 開け払うあけはらうto open
• 開豁かいかつopen
• 広々としたひろびろとしたopen
• 拓くひらくto open (e.g. path)
• 開放的かいほうてきopen (attitude, etc.)
• おっぴらopen
• 披くひらくto open
• おおびらopen
• 開かいopen
• 多孔たこうporous
• 表立ったおもてだったpublic
• 曠然こうぜんextensive
• 観血的かんけつてきsurgical
• あからさまplain
• 開催中かいさいちゅうin session
• あきらさまplain
• びりびり(tear) to pieces
• 始めるはじめるto start up (a business, society, etc.)
• オープンopen
• 豊かゆたかopen (mind)
• 広げるひろげるto unfold
• 開口かいこうopen
• 呼び出すよびだすto invoke (e.g. a subroutine)
• 堂々どうどうfair
• フリーダムfree
• 暴くあばくto open (a grave)
• 切り開くきりひらくto clear (land)
• むき出しむきだしfrank
• 露あらわpublic
• おっ開くおっぴらくto open
• 開けっぴろげあけっぴろげfrank
• おっぴろげるto unfold
• 切るきるto open (something sealed)
• 開けるひらけるto open (of a new road, railway, etc.)
• 通すとおすto connect (e.g. two places)
• 気持ちいいきもちいいagreeable
• 気持ちがいいきもちがいいagreeable
• 起こすおこすto start
• 蓋を開けるふたをあけるto open (of a theatre)