Captionary

Learn languages on YouTube, Netflix and Apple TV+ with dual subtitles, a pop-up dictionary, saved words and AI explanations.

Turn videos and reading into language practice with Captionary. Watch YouTube, Netflix and Apple TV+ with the original subtitles and a translation together. Click a word or select a phrase to look it up, save it, and return to the video. LEARN WHILE WATCHING • Show two subtitle languages together, with optional romanization for supported scripts. • Browse and search the subtitle list, jump to a line, or repeat it. • Pause after each line, adjust playback speed, and use customizable keyboard shortcuts. • Hide translations until you hover when you want to test your understanding. UNDERSTAND WORDS IN CONTEXT • Look up words and phrases with Wiktionary and links to external dictionaries. • Listen to pronunciation using your browser's available voices. • Configure an AI provider for vocabulary explanations, sentence breakdowns, and follow-up questions. BUILD YOUR VOCABULARY • Save words and phrases with their context and source timestamp. • Mark vocabulary as learning or known and recognize saved words when they appear again. • Review flashcards and export vocabulary to CSV, an Anki-compatible text file, or a JSON backup. READ AND PRACTICE • Paste text or open TXT, SRT, and VTT files in the reader. • Send a page to the reader from the extension's toolbar or right-click menu. • Practice with a local video file and a separate subtitle file. CHOOSE YOUR AI SETUP AI features are optional. Configure a supported cloud provider with your own API key, a local Ollama or LM Studio server, or Chrome's built-in AI where available. Optional ChatGPT account sign-in uses an undocumented integration whose availability may change; Captionary is not affiliated with OpenAI. Cloud providers may charge for usage, and account-based features depend on your plan and usage limits. You can choose how much context to share and whether to include a video title in supported explanation requests. Your settings and saved vocabulary are stored in your browser. Online dictionary requests and configured cloud AI features send the relevant text to those services. See the privacy policy for details. Captionary works with the web players at youtube.com, netflix.com, and tv.apple.com. Subtitle availability varies by video, language, and platform. Netflix and Apple TV+ may require their own subscriptions. Chrome's built-in AI and translation features depend on browser, hardware, and language support. AI answers can contain mistakes. Captionary is an independent extension and is not affiliated with or endorsed by YouTube, Netflix, or Apple. INTERFACE LANGUAGES English, Simplified Chinese, Traditional Chinese, and Japanese. A first-run guide helps you choose your languages and try the core study tools. AI setup can be skipped.