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Side-by-side: what they do, what they cost, what Kai actually thinks. Pass up to 4 tools via ?tools=claude,chatgpt,gemini.
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Duolingo Max
A
ChatGPT
S
OpenRouter
S
TaglineDuolingo + AI. Explain My Answer + Roleplay features.The default. Strongest ecosystem + best multimodal breadth.One API, every model. Pay-as-you-go, no subscriptions.
Categoryeducationchatdev platform
Pricing$30/mo (or ~$168/yr)Free + $20/mo Plus + $200/mo ProPay per token — model-dependent
Best forLanguage learners who've outgrown basic Duolingo.General use, voice chat, image generation, first-time AI users.Developers experimenting across models. Apps that want fallback logic.
Strengths
  • Explain My Answer = personal tutor for every mistake
  • Roleplay = real conversation practice
  • Gamification that actually sticks
  • Great voice mode
  • Huge plugin/custom GPT ecosystem
  • Strong image generation (DALL-E built in)
  • Code Interpreter
  • 300+ models from one endpoint
  • Automatic fallbacks between providers
  • No subscription — just pay what you use
Weaknesses
  • Pricey vs free Duolingo
  • Conversation AI still stiff sometimes
  • Reasoning quality varies by mode
  • Can be verbose
  • Confabulates on niche facts
  • Slight markup over direct API
  • Some provider features not exposed
Kai's verdictA-tier. If you already love Duolingo, worth it. If starting fresh, try ChatGPT Voice instead.S-tier all-rounder. If you want one tool that does everything okay-to-great, this is it.S-tier for model-shopping. I use this for every prototype before committing.
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