キャパい

キャパい (kyapai) is a piece of Japanese Gen-Z slang meaning that your capacity is full — you're overwhelmed, overloaded, or running on empty. It is an い-adjective coinage built from キャパ, itself a clipping of キャパシティ (kyapashiti, from English capacity). In February 2025 it was voted the No. 1 most interesting youth word in a widely reported ranking, beating メロい into second place.

Meaning

キャパい describes the feeling of being at or near the limit of what you can mentally or emotionally handle. It is essentially a shortened, adjective-ified version of キャパオーバー (kyapa ōbā, "capacity over") — the moment your tasks, emotions, or stimulation exceed your personal bandwidth.

Crucially, キャパい usually signals being mildly fried rather than completely broken. It's the overwhelmed-but-still-functioning zone: too much going on, brain full, mentally tired. Think "I'm maxed out" or "I can't even right now" rather than a total breakdown.

Because it is treated as a regular い-adjective, it conjugates naturally:

A secondary, positive usage also circulates online, where キャパい is stretched to mean "so overwhelming it's amazing" — an emotional overload of admiration toward an idol or a cute thing (e.g. 推しの笑顔きゃぱい, "my fave's smile is too much"). The dominant everyday meaning, however, remains the negative "I'm overloaded."

Usage

キャパい is spoken casually among friends and posted on social media, typically about schedules, workloads, or emotional saturation.

今日、予定詰めすぎてキャパい。 Kyō, yotei tsumesugite kyapai. "I've crammed too much into today, I'm totally maxed out."

この情報量、キャパい… Kono jōhōryō, kyapai… "This much information — my brain's full."

バイトと課題が重なってマジでキャパいんだけど。 Baito to kadai ga kasanatte maji de kyapai n da kedo. "Work and assignments are piling up at once, I'm seriously overloaded."

It frequently pairs with intensifiers like マジ (maji, "seriously") or もう (mō, "already/ugh"), and stands alone as a one-word reaction:

——もうキャパい。 ——Mō kyapai. "...Ugh, I'm done."

Cultural Context

キャパい is a textbook example of how modern Japanese youth slang is built: take a loanword, clip it short, and bolt on the い-adjective ending. The same machinery produced エモい (emoi, "emotional/moving," from emotional) and ナウい (naui, "now/trendy") in earlier eras. キャパい follows キャパシティ → キャパ → キャパい, compressing a four-mora English borrowing into a snappy native-sounding adjective.

The word's breakout is widely credited to gyaru model and TV personality ゆうちゃみ (Yuuchami), who reportedly reasoned that キャパオーバー was too long and that キャパい would do the job — and used it on television, including in a commercial. From there it spread rapidly across TikTok, X (Twitter), and Instagram.

That trajectory paid off in early 2025, when a survey of several thousand respondents named キャパい the most interesting youth word of the year, edging out メロい ("smitten, charmed"). Voters singled out its guessability and ease of pronunciation — even people outside the Gen-Z bubble can roughly infer the meaning from キャパ, which lowers the barrier to adoption.

キャパい also reflects a broader trend in Gen-Z communication: lightweight, self-deprecating vocabulary for naming everyday mental load. Alongside terms about burnout, social fatigue, and being "too online," キャパい gives young people a quick, low-drama way to flag that they've simply had enough for one day — overwhelmed, but not necessarily in crisis.

Related Terms

• キャパオーバー (kyapa ōbā) — the longer parent phrase, "over capacity / capacity overload."
• キャパシティ (kyapashiti) — the original loanword, "capacity."
• メロい (meroi) — 2025's runner-up youth word, "smitten/charmed."
• エモい (emoi) — "emotional, moving, nostalgic"; the same い-adjective-from-loanword pattern.