Chinese proofreading and local AI guide
LocuText is a text proofreading app that runs in your browser. It checks common Chinese typos, a limited set of Chinese grammar patterns, and English grammar. No account or draft upload is needed; you decide every edit.
Content reviewed:
Quick check, MacBERT, or Qwen?
- Quick check: a starting point for emails, article drafts, and mixed Chinese and English text. It uses a limited Chinese rule set and dictionary plus Harper for English, without downloading an AI model. Optional style suggestions are off by default.
- MacBERT: the default local AI model corrects Chinese typos by replacing individual characters; Harper still checks English. It is not a full Chinese grammar checker and does not insert or delete characters, fix punctuation, or polish prose.
- Qwen: choose and download this optional model for broader Chinese and English corrections or light polishing. It can miss errors, make incorrect edits, or change your meaning, so review each suggestion.
The editor needs JavaScript, and quick check uses WebAssembly. Local AI also needs a usable WebGPU adapter, sufficient storage, and GPU memory. Quick check remains available when local AI is unsupported; the app does not switch to cloud proofreading.
How much text can I check?
- Quick check
- Up to 20,000 characters per draft, useful for a first pass through longer text.
- Local AI
- Up to 3,000 characters and 80 sentences per check. Work on longer drafts in sections.
- Files
- Type or paste plain text, or import and export TXT. Word and PDF files are not supported.
- English spelling
- Harper uses American English by default. The interface language does not change the English dialect.
Characters are not the same as English words. Keep your source file and copy or export the reviewed draft: the original and review decisions remain only in the current page. Local AI also has sentence-length, browser memory, and GPU memory limits. A failed check is reported as a failure, not a clean result.
What can the Chinese checks find?
Quick check covers some common typos, repeated text, punctuation and bracket issues, and a few bounded patterns involving classifiers, 的／地／得, and sentence structure. Examples from the current rules include:
- “他迫不急待地打开礼物。” → suggests replacing “迫不急待” with “迫不及待”.
- “我们会再接再励。” → suggests replacing “再接再励” with “再接再厉”.
- “请确认，，然后继续。” → flags the repeated comma and suggests keeping one.
When a grammar rule changes text—and when it leaves it alone
These sentences come from existing rule regression cases. They illustrate specific boundaries, not complete grammar coverage.
| Input | Result and reason |
|---|---|
| 现场起码至少需要两名值班员。 | Suggests 现场至少需要两名值班员。, removing a redundant expression. |
| 今天必需完成验收。 | Suggests 今天必须完成验收。; 必须 modifies the action here. |
| 食物属于生活必需品。 | Leaves the sentence unchanged. The word 必需品 should keep 必需. |
| 她认真得核对了日期。 | Suggests 她认真地核对了日期。, using 地 before the action. |
| 会议至少需要十人以上参加。 | Asks you to review the numerical boundary. It offers no automatic replacement and is not applied by Finalize. |
These examples do not establish comprehensive Chinese grammar coverage or an accuracy rate. Complex sentences, contextual logic, facts, and proper names still need human judgment. No suggestions does not mean a draft is error-free. Ambiguous issues and notices without a safe replacement need manual review.
See the English grammar checker guide for English coverage and limitations.
How do I review a long draft?
- Paste text or import a TXT file, choose an engine, and start a check.
- Read the continuous full-document diff. Select a highlighted change or its number to accept, reject, or edit it yourself, without paging through individual sentences.
- For batch changes, switch to Finalize to see a read-only preview before confirming pending edits. Rejected suggestions stay rejected. After editing the draft yourself, run a new check.
- Copy or export the reviewed text as TXT. You can undo changes and view the imported original, but drafts are not saved automatically when you close the page.
Optional style suggestions are off by default. They are wording preferences, not necessarily errors. If an English name or technical term is flagged incorrectly, choose Ignore spelling in this draft. It applies only to the current draft; other grammar checks still run.
What do I need for offline proofreading?
Open the editor online first and check that the app and quick-check files are ready in the Privacy & offline panel. You can then reopen the same URL in the same browser offline. Local AI additionally requires the complete selected model and runtime, downloaded at your request in advance. An available webpage does not mean a model is fully cached.
Browsers may evict caches, and another browser or device cannot reuse them. Check each cache status and save your draft before going offline. The proofreading code does not upload drafts; hosting and model download providers may process connection and performance data. See the privacy and offline notice.
Frequently asked questions
Can I check Traditional Chinese?
You can enter Traditional Chinese, but the current Chinese rules and default model mainly target Simplified Chinese. Equal typo or grammar correction quality is not guaranteed. The app does not automatically convert drafts to Simplified Chinese; review every suggestion.
Can I mix Chinese and English in one draft?
Yes. Quick check uses Chinese rules and English Harper checks together. Changing the interface language only changes controls and descriptions; it does not translate your draft or download a model.
Can I use a phone as well as a computer?
The interface adapts to narrow screens, while a computer offers more room for reviewing long drafts. Local AI depends on your device, browser, and available memory. Real-phone acceptance testing has not been completed, so model and offline behavior are not guaranteed across phones.
Does it support Word, PDF, translation, or cloud AI?
The app supports pasted plain text and TXT import and export. It does not currently provide Word, PDF, translation, or cloud AI features. No registration is needed.
Related pages
English grammar checker · Privacy & offline use · Saving, caches, and other questions · 中文版使用指南
Checking engines and references
These descriptions were checked against LocuText's implementation and the upstream references below. An upstream feature is not necessarily available in LocuText, and these sources do not certify this app's accuracy.
- Harper's local linting interface: the basis for English checks and suggestions.
- MacBERT Chinese spelling correction model card: the purpose and source of the Chinese typo model.
- WebLLM documentation: the browser inference framework used for the optional Qwen model.