DualCap — Bilingual Captions & Language Learning

About

Learn a language the way your brain actually works — through stories you enjoy.
DualCap puts live bilingual captions on any video you watch. See the original subtitle and the translation side by side. Click any word to look it up. Click the translation to get a full grammar explanation. Save sentences to your personal dictionary. No separate study sessions. No app switching. Just watch and absorb.

HOW IT WORKS
Turn on subtitles in the video player. DualCap intercepts them and shows both lines as a clean overlay directly on the video. Translations arrive in under 100ms, powered by Groq AI.


FEATURES
— Live bilingual overlay: draggable, resizable, works in fullscreen
— Grammar breakdowns (A2–C2): tense, sentence structure, word-by-word roles, CEFR level, key insight, learner tip, and example sentences using the same pattern
— Word lookup: definition, pronunciation, gender, part of speech, and 2 examples
— Personal dictionary: save any sentence, meanings are auto-fetched, export as PDF
— Loop mode: press L to replay the current line for shadowing practice
COMPATIBLE WITH
DualCap works on any streaming site that uses standard subtitle tracks, such as Netflix, YouTube, and Disney+.


SETUP

Install DualCap
Get a free Groq API key at console.groq.com (no credit card)
Click the DualCap icon → Settings → paste your key
Open a video, enable subtitles, start learning

PRIVACY
DualCap does not collect any personal data. Subtitle text is sent to Groq's API for translation only. Everything else stays on your device.