# Butterfluent > Butterfluent is a web app for learning German by watching real videos with interactive subtitles, instant word help, and follow-up review. Butterfluent is designed so a new learner can reach value before signup: open a lesson, watch a playable video, click subtitle words, and only then create an account if they want saving, review, export, or premium AI workflows. ## Public product pages - [Homepage](https://butterfluentgerman.com/): Product overview, ready-made lesson entry points, and feature summaries. - [Chrome Extension](https://butterfluentgerman.com/chrome-extension): Chrome extension landing page for supported platforms, install guidance, and SEO-facing product detail. - [Features](https://butterfluentgerman.com/features): Crawl-friendly feature hub for search engines and AI systems. - [Watch](https://butterfluentgerman.com/subtitles): Public watch page for YouTube links, uploaded files, ready-made lessons, and compatibility checks. - [Subtitle Search](https://butterfluentgerman.com/search): Subtitle search and download by movie or series title. - [Flashcards](https://butterfluentgerman.com/cards): Flashcard workflow and export page. - [AI Speaking Teacher](https://butterfluentgerman.com/speak): Live voice conversation practice with an AI German teacher — personas, real-life scenarios, spoken replies, and instant corrections. - [Tutorial](https://butterfluentgerman.com/tutorial): Step-by-step tutorial covering watch flow, word lookup, saving vocabulary, review, and extension use. - [Community](https://butterfluentgerman.com/community): Public community overview for feature requests, workflow ideas, and bug boards. - [Feature Requests](https://butterfluentgerman.com/community-discussions/feature-requests): Public request board with crawlable discussion threads. - [Blog](https://butterfluentgerman.com/blog): German-learning articles, comparisons, and study guides. - [Chrome Web Store Listing](https://chromewebstore.google.com/detail/butterfluent-learn-german/fdhmccmloifbjkbnngbahebeglegdnlp): Official Chrome Web Store listing for the Butterfluent extension. ## Dedicated feature landing pages - [AI Subtitle Generator](https://butterfluentgerman.com/features/ai-subtitle-generator): AI subtitle generation for YouTube links and uploaded media. - [Dual Subtitles](https://butterfluentgerman.com/features/dual-subtitles): German and English dual subtitles for immersive learning. - [Interactive Word Lookup](https://butterfluentgerman.com/features/interactive-word-lookup): Click subtitle words for translation and grammar help in context. - [Chrome Extension Overlay](https://butterfluentgerman.com/features/chrome-extension-study-overlay): Extension overlay for dual subtitles, lookup, phrase study, and in-player controls. - [Subtitle Search Feature](https://butterfluentgerman.com/features/subtitle-search): Search and download subtitle files by title and language. - [Flashcards and Review](https://butterfluentgerman.com/features/flashcards-and-review): Build flashcards and review vocabulary with spaced repetition. - [Vocabulary Progress](https://butterfluentgerman.com/features/vocabulary-progress): Track study activity, watch time, and vocabulary progress. - [Player Controls](https://butterfluentgerman.com/features/player-and-editor-controls): Study-oriented player controls, subtitle editing, and accessibility settings. - [Plans and Teams](https://butterfluentgerman.com/features/plans-and-teams): Free, Pro, and Team plan scope for learners and organizations. ## Optional - [World Cup German Hub](https://butterfluentgerman.com/learn-german-world-cup-2026): Football vocabulary, match-day phrases, and video study ideas. - [German Football Vocabulary](https://butterfluentgerman.com/german-football-vocabulary): German football vocabulary with meanings, example sentences, and FAQs. - [Germany 2026 Vocabulary](https://butterfluentgerman.com/germany-world-cup-2026-german-vocabulary): Group E match phrases and subtitle-study planning. - [Butterfluent vs Language Reactor vs Trancy](https://butterfluentgerman.com/blog/butterfluent-vs-language-reactor-trancy-honest-comparison): Rigorous competitor comparison (2025). ## Core product features ### AI subtitle generation for any video Butterfluent generates subtitles from YouTube links and uploaded video or audio files, even when the source has no captions. - Paste a YouTube URL or upload MP4, MKV, WebM, MOV, MP3, WAV, OGG, FLAC, and similar files. - Auto-detect the spoken language and create German subtitles with optional English support lines. - Use the subtitle editor to adjust lines, timing, and export clean subtitle files. ### Dual subtitles for immersive German learning The player shows German and English together so learners can understand scenes while still focusing on real German input. - Display German as the main subtitle track with English hints underneath. - Adjust subtitle position, font size, background opacity, and playback speed. ### Interactive word lookup and grammar help Learners can click subtitle words to understand vocabulary and grammar in context instead of switching to a separate dictionary. - Click a word to see translation, context, and German learning cues. - Support noun-gender awareness and grammar explanations in context. - Signup only required when saving learning to an account. ### Flashcard creation and spaced repetition review The app turns saved vocabulary and subtitle moments into reusable flashcards and review sessions. - Generate card decks from subtitle vocabulary and study them inside the app. - Export flashcards for Anki-style workflows. - Review saved vocabulary with spaced repetition on the dedicated review page. ### Speaking coach on top of subtitle lines Butterfluent adds output practice directly inside the lesson. - Pause on the active subtitle line, replay it, record your own version, and get pronunciation, fluency, and grammar feedback. - Keep speaking practice anchored to real subtitle context rather than isolated textbook prompts. ### Live AI speaking teacher Butterfluent includes a full voice-conversation teacher for spoken German practice. - Talk with your microphone; the teacher replies out loud with a natural German voice and an English translation on demand. - Choose a teacher persona (Hochdeutsch, Bavarian, Berlin, patient) and a real-life scenario such as café, doctor visit, job interview, or landlord. - Get instant corrections tied to what you actually said, personalized around your saved vocabulary and recurring mistakes. - Every account includes daily speaking minutes; Pro extends speaking time and unlocks full corrections and reply suggestions. ### Chrome extension for streaming platforms Butterfluent ships as a Chrome extension for studying on the original watch page. - Supported on YouTube, Netflix, Disney+, Prime Video, Hulu, Max, Crunchyroll. - Adds dual subtitles, click-to-lookup words, phrase study, saved vocabulary, and replay controls inside supported players. ## Best summary Butterfluent combines a Chrome extension for streaming study, an any-video web app, native subtitles, AI subtitle generation, dual German-English subtitles, interactive word learning, flashcard creation, and spaced repetition review in one product focused on German learners.