Developer Builds Free AI Tool to Grade Mandarin Tones and HSK Speaking Level

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A developer and native Mandarin speaker has created ToneTutor, a free AI-powered tool that assesses spoken Mandarin and estimates a user's HSK proficiency level in real time. The tool addresses a gap in existing resources, as most learners cannot self-assess their HSKK speaking level and professional tutors are costly. ToneTutor conducts a three-minute spoken test, then uses Google's Gemini 2.5 Flash model to analyze tone accuracy, grammar, and vocabulary range. The stack includes a React and TypeScript frontend, a FastAPI backend hosted on Google Cloud Run, and Firestore for session storage. The project is available free for up to three sessions at tonetutor.tefusiang.com, with an open-source release planned.

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