Rime-Based iOS Keyboard Zihao Brings Custom Chinese Input to iPhone and iPad

On first launch, Zihao deploys Wusong Pinyin on the device and downloads a sentence-level grammar model called Zihao Spoken, about 6.8 MB, optimized from Chinese Wikipedia colloquial text. The keyboard supports 26-key full pinyin, nine-grid input and Xiaohe double pinyin, with auxiliary radical codes in Xiaohe double pinyin, such as typing yj for the speech radical. It outputs simplified Chinese, traditional Chinese, Taiwan traditional Chinese and Hong Kong traditional Chinese, though the last three are not yet natively supported and will be optimized later through methods including Daqian Zhuyin. Shortcuts include rqsjxqnl for date, time, day of week and lunar calendar, R1234 for uppercase amounts, U62fc for code-based input and vfh for symbols. Wusong Pinyin can be updated in the app after users review changes, and learned words are not affected.

The app also lets users import their own Rime schemes. In the Schemes section, users can import a Rime configuration folder, ZIP file, YAML file or text dictionary, or enter a public GitHub repository such as iDvel/rime-ice, choose a branch and directory, and set daily or weekly automatic updates. Schemes compile on the phone without passing through a server. Users can add their own configuration files. Typed words are saved in Rime format in an iCloud Drive sync folder; by pointing sync_dir in Squirrel's installation.yaml to the same folder, users can merge phone and Mac user dictionaries, and the app can copy the setting with one tap.

Zihao adds touch-point error correction on top of Rime to address thumb mispresses on mobile. It combines the finger's touch location with pinyin rules to infer the intended word, while the original pinyin remains in the candidate list. A hard rule prevents corrections from breaking correct input: if the typed letters themselves form a word, that word ranks first. For example, typing zihao gives the word for pride first, not the word for preference. In long sentences, two or three wrong letters can be corrected together. In the developer's simulated tests, first-try accuracy for sentences with two wrong letters rose from 36% to 56%, and for sentences with three wrong letters from 26% to 53%, while correct sentences were not broken. Candidates appear all at once rather than switching after initial display.

A separate small context model, about 5 MB, reads text already written before the cursor to choose among homophones. For shuxue, which can mean mathematics or blood transfusion, if the preceding text says the patient has lost a lot of blood and the doctor is about to treat him, the first candidate becomes blood transfusion. The model runs entirely on the phone, adjusts the first candidate only when it is clearly more suitable, and user selection habits still take priority.

Keyboard details include an emoji key that can be changed to a Chinese/English switch with a long press for the other function; email and URL fields automatically switch to English with @./ next to the space bar; the English-mode symbol page matches the iOS English keyboard with half-width symbols; the return key shows Confirm during pinyin input and Send or Search after input; and on iPhone Duo in landscape, the 26-key layout can split into left and right halves, while the nine-grid layout uses a wide-screen layout referencing Apple's design.

Zihao says typing, error correction, learning and its two models all run on the phone and are not uploaded. iOS requires Full Access for the keyboard to read dictionaries and settings stored in the app, and enabling it does not cause Zihao to upload anything. The app's AI features, including translation, polishing, summary, reply and translate-as-you-type, do not bundle any service. Users enter their own API keys for OpenAI, Claude, Gemini, DeepSeek or a translation interface, and requests go directly from the phone to the chosen provider. From version 1.0.9, phone numbers, ID numbers, bank card numbers, emails and verification codes are replaced with placeholders before sending and restored on the phone after the result returns.

Typing-related features are free, including 26-key and nine-grid input, Xiaohe double pinyin, error correction, learning, quick phrases and Rime scheme import. Zihao Pro is a one-time purchase with no subscription and unlocks translate-as-you-type, AI scripts, all themes and background images, and multi-device sync. Zihao is free on the App Store; the first release does not include mainland China or the EU. Its website is hareime.com, with a Rime usage page at hareime.com/rime-ios.