Back to Portfolio
AI/Education

KoeJLPT — Voice-First JLPT Preparation App

View Code
Next.js 16React 19TypeScriptTailwind CSSPostgreSQLPrismaClerkElevenLabsGoogle Cloud Speech-to-Text

A voice-first Japanese Language Proficiency Test (JLPT) preparation app built with Next.js 16 and React 19. KoeJLPT helps learners build vocabulary and speaking confidence through AI-powered voice conversations and automatic pronunciation grading.

Features

  • Vocabulary Study: Level-based word browsing (N5–N1) with audio playback and save functionality
  • Voice Conversations: Real-time WebRTC conversations with an AI partner (Fumi) — exclusively in Japanese
  • Pronunciation Practice: Three practice modes with automatic grading via Google Cloud Speech-to-Text
  • Study Dashboard: Statistics, study streaks, and quick navigation across all modes
  • Study History: Persistent tracking across vocabulary sessions, conversations, and pronunciation attempts
  • Onboarding Flow: First-time user level selection and goal setting

Tech Stack

Next.js 16 · React 19 · TypeScript · Tailwind CSS v4 · PostgreSQL (Neon) · Prisma v6 · Clerk · ElevenLabs (TTS & Voice Agent) · Google Cloud Speech-to-Text · MyMemory Translation API