Frequently Asked
Questions

Yes! Stemmy is completely free with generous daily limits for definitions and text-to-speech. You get free AI-powered definitions, pronunciation audio, vocabulary wallet, spaced repetition, immersion mode, and AI-generated stories — all included at no cost. Power users can add their own API key to remove limits entirely.

Absolutely. Your data stays on your device. All vocabulary, settings, and progress are stored locally in chrome.storage.local and never leave your browser. The only external communication happens when you actively request a definition (sent to Mistral AI) or pronunciation (sent to ElevenLabs). We don't use cookies, tracking, analytics, or telemetry of any kind.

Stemmy uses Mistral AI for definitions, context analysis, immersion rewrites, and story generation. For text-to-speech pronunciation, it uses ElevenLabs with natural-sounding voices. Both services are best-in-class and deliver fast, accurate results.

Yes — Stemmy works on virtually every website you visit. Whether you're reading articles, research papers, documentation, or social media, you can highlight any word for an instant definition. The only exceptions are Chrome's internal pages (like chrome://settings) and the Chrome Web Store, which are restricted by Chrome's security model.

Yes! If you have your own Mistral AI or ElevenLabs API key, you can add it in the extension's settings. Your key is stored locally on your device and is never shared with us. Using your own key removes the daily free-tier limits, giving you unlimited definitions and pronunciation audio.

Word Immersion turns any webpage into a learning environment. When activated, Stemmy's X-Ray scanner finds your saved vocabulary words on the page and highlights them. Hover any highlighted word to instantly review its definition. It's contextual reinforcement — you see your words in real-world sentences, which dramatically improves long-term retention.

Stemmy handles minimal data, all stored locally:

• Vocabulary & definitions — stored locally on your device
• Learning progress & settings — stored locally
• Selected word + context — sent to Mistral AI only when you request a definition
• Word text — sent to ElevenLabs only when you tap pronunciation
• Email — only if you voluntarily join the waitlist

We never collect browsing history, page content, or personal information. See our full data practices above in "Is my data secure?"