Dual Subtitles & Video Hover Dictionary
Synchronized Bilingual Subtitles, 0.1s Hover Dictionary HUD & 1-Click Anki Exporter for YouTube, Netflix & Udemy
Technical Highlights
- Synchronized 2-Tier Bilingual Subtitles on YouTube, Netflix 4K & Udemy
- 0.1s Hover Dictionary HUD with 3-Tier Zero-Latency Cache (0ms hit)
- Smart Auto-Pause & Resume State Machine on word hover
- Browser-Native Web Speech Audio TTS with Ear-Protection Volume Clamping
- Precision Shadowing Hotkeys: Replay (S), Previous (A), Next (D), Toggle Translation (V)
- 1-Click Anki (.tsv) & CSV Vocabulary Bank Exporter with sentence context
- Input Element Shielding: Hotkeys automatically disable inside search & comment boxes
- 100% On-Device Privacy: Zero watch history tracking, zero external server overhead
Market Differentiators
Why We Built This: Legacy Flaws vs Modern V3 Architecture
Engineered from first principles to resolve real user complaints, abandoned legacy codebases, and predatory subscription traps.
Performance & 4K Streaming Lag
Language Reactor (LLN) has a 5MB+ bundle that causes severe frame drops and lag on 4K Netflix streaming; charges $6/mo ($72/yr).
< 500KB zero-lag engine engineered for smooth 4K HDR playback on YouTube and Netflix under a $19.50 lifetime deal.
Manifest V2 Deprecation & Maintenance
YouTube Bilingual Subtitles (142k users, 4.4★) abandoned for 1,590+ days on Manifest V2; frequently desyncs.
100% Manifest V3 native architecture with resilient DOM mutation observers and active ongoing updates.
Udemy Course Support
Existing tools only work on YouTube and Netflix, completely ignoring educational video courseware.
Dedicated platform adapter for Udemy courses, enabling developers and professionals to learn in foreign languages.
Workflow Alignment
Engineered for High-Performance Workflows
Language Learners & Shadowing Students
Developers & Tech Professionals
Global Media & Film Enthusiasts
Engineering Overview
Master foreign languages while enjoying your favorite movies, series, and technical courses. Dual Subtitles renders clean, synchronized bilingual subtitle streams across YouTube, Netflix (including 4K HDR), and Udemy without video lag or audio desync.
Hover over any unfamiliar word in the subtitles to instantly pause playback, view comprehensive definitions with phonetics, and hear clear native pronunciation via Web Speech API with ear-protection volume clamping. Video playback automatically resumes when your cursor leaves.
Engineered for language shadowing drills with single-key shortcuts: replay sentence (S), jump to previous (A), advance to next (D), or toggle secondary translation (V) for listening tests. Save words with full spoken sentence context and export directly to Anki TSV flashcard decks in 1 click.
Pricing
Start Free. Upgrade Anytime for Lifetime Power.
Instant in-app activation via Dodo Payments. Transparent lifetime license without recurring subscription traps.
Free Starter
Core dual subtitles and daily dictionary lookups for everyday learners
What's Included:
- Synchronized bilingual dual subtitles on YouTube, Netflix & Udemy
- 0.1s hover dictionary with native pronunciation audio
- Keyboard shortcuts for sentence replay & navigation
- Save up to 10 vocabulary words per day
- Standard subtitle styling controls
Early Bird Pro Lifetime
Unlimited vocabulary study & flashcard exports for language mastery (In-App Upgrade)
What's Included:
- Unlimited daily vocabulary saves & dictionary lookups
- 1-Click Anki (.tsv) ready flashcard deck exports
- Full CSV, Excel & TSV vocabulary downloads
- Custom subtitle color themes & opacity controls
- Instant Dodo Payments license auto-activation
- Lifetime commercial license with 3-device browser sync
Install the extension for free using the store buttons at the top of the page. Pro features are activated seamlessly inside the extension.