A little help, close at hand.

Core Chinese input, candidates and on-device handwriting are available free. Plus adds prediction, appearance customization, key sizing and manual iCloud sync. InkGold and Recessed are Plus-exclusive.

AI uses Credits and separate consent. Buying Credits does not unlock Plus customization or sync. Current purchase details are shown in the app.

Open “AI 與 Credits” → “恢復購買”, using the Apple Account that made the purchase. If access still looks wrong, contact support with the app version and the product purchased; do not send passwords or verification codes.

With Personal Learning enabled, KOI can learn a supported correction when a local Chinese question is visible: delete its last character, replace it with a different Chinese character, then continue typing. It verifies the observed context and later input; it does not learn every edit.

Manage entries in 設定 → 輸入與候選 → 自動更正學習. Local learning does not need AI consent. A saved entry does not guarantee that every later suggestion will apply it.

iOS gives a third-party keyboard no networking capability at all without this permission. KOI needs it to connect to the AI features, to read the clipboard (only at the moment you press Paste), to update the handwriting model, and to archive generated images in the app's shared image library.

Leaving it off is completely fine. The five input methods, candidates, learning, handwriting, symbols and cursor controls all still work. What you lose is AI access, paste, handwriting-model updates, and shared image-library archiving.

Ordinary input, candidate ranking and learning run on your device and are not sent keystroke by keystroke to KOI servers.

When you explicitly agree to AI sharing and execute a KOI Agent action, it sends your instruction, applicable conversation and the previewed selection/before/after context, capped at 2,000 Unicode scalar values and 4,000 UTF-8 bytes. You can withdraw AI sharing consent in “AI 與 Credits”.

Optional sync sends settings and learning data to your private CloudKit. The App Store version does not enable internal developer diagnostics. See the privacy policy for recipients and retention.

Choose the Chinese input mode in the KOI app's settings. Cangjie, Quick, Stroke, Jyutping and Zhuyin each have their own keyboard layout.

No. The Hong Kong Traditional Chinese handwriting model is built into the app, so it writes just as well in aeroplane mode. A connection is used only to update the model, and it works without updating.

KOI may offer near-miss candidates after exact matches. Check them before committing. Press delete twice in succession to clear a composition.

Candidates cover the Han characters in the Basic Multilingual Plane (BMP). A small number of extremely rare extension characters (Unicode Ext B and beyond) are not included yet.

If a character is in common use and you cannot find it, email us with the code you typed and the character you wanted.

Sync requires Plus, a KOI account and iCloud. Use the same iCloud account on both devices.

Enable sync and trigger it manually in the app. Sync is off by default and does not run in the background.

Credits are used only for KOI Agent's AI actions. Everyday typing, candidates and handwriting recognition never cost Credits.

Reply, rewrite and translate cost 1 each, asking a question costs 2, generating a sticker costs 6, and generating an image costs 18.

A subscription grants 250 Credits each month, and each grant is valid for 60 days from the day it is issued; Credit packs bought separately do not expire.

To cancel: iOS Settings → your Apple Account → Subscriptions → KOI → Cancel Subscription. You keep access until the end of the current period.

Refunds are handled by Apple, not by KOI. Request one at reportaproblem.apple.com.

KOI services and bundled SDKs process operational, performance, diagnostic and usage data to provide and protect features. KOI uses no advertising identifier or cross-app advertising tracking. See the privacy policy for details and your choices.