Vocabulary Builder

Build vocabulary while you read. Right-click any word on any web page to define, translate, and save it — then review with flashcards and spaced repetition.

Vocabulary Builder turns the web itself into your study material. Look up unfamiliar words inline, translate to 12 languages, and save them to a personal deck that resurfaces on the right schedule. Works on regular pages and PDFs, in light and dark mode.

KEY FEATURES
✓ Right-click word lookup
✓ Translate in 12 languages
✓ Bring-your-own AI translation
✓ Flashcards with SM-2 spaced repetition — review at the optimal interval
✓ Audio pronunciation
✓ PDF side panel
✓ Highlight & remember — saved words stay highlighted next time you visit the page
✓ Streaks, XP, and daily goals — gentle gamification keeps you coming back
✓ Daily reminders — configurable notifications for study sessions
✓ Keyboard shortcuts — Alt+M / Cmd+Shift+M and customizable hotkeys
✓ Dark mode — system-aware with a manual toggle
✓ Cross-device settings sync — preferences and API keys roam across your Chrome browsers
✓ Export & import — back up your vocabulary as JSON anytime

PERFECT FOR
- Language learners reading articles, blogs, and documentation in a non-native language
- Students studying
- Researchers and professionals encountering domain-specific jargon
- Bilingual readers who want an instant, unobtrusive translator
- Anyone trying to build a daily reading habit and remember more of what they read

HOW IT WORKS
1. Install Vocabulary Builder and pin it to your toolbar
2. Browse any web page or PDF and select a word
3. Right-click → "Look up word" — definition, translation, and audio appear inline
4. Save the word with one click; it joins your flashcard deck
5. Review later — the SM-2 algorithm shows each word at the right interval

PRIVACY
- Vocabulary, study statistics, and progress are stored locally on your device using chrome.storage.local. They are never uploaded.
- Settings (theme, language pairs, hotkeys) and your AI-provider API keys sync across your signed-in Chrome browsers via chrome.storage.sync, so you don't have to re-enter them on a new machine.
- Selected text is sent to translation and dictionary APIs only when you trigger a lookup. We never read or transmit full page contents.
- AI translation uses YOUR OWN API key going directly to your chosen provider. The extension does not host or proxy this traffic.
- No analytics, no telemetry, no account required.

PERMISSIONS EXPLAINED
- "Storage" — saves your vocabulary, stats, and settings on your device
- "Context menus" — adds the right-click "Look up word" item
- "Active tab" — reads the focused tab only when you invoke a lookup
- "Notifications" — shows daily study reminders (you can turn them off)
- "Alarms" — schedules the daily reminder time
- "Side panel" — opens the lookup panel for PDFs
- Network access is limited to dictionary, translation, and AI endpoints listed in the manifest. AI endpoints are only contacted when you opt in.

Free, open source, and ad-free. Install Vocabulary Builder and start turning every page you read into vocabulary you actually remember.