Visual Grammar Subtitles

Overlay local subtitles on any web video with colour-coded grammar, word cards and display-time control for language learning.

Visual Grammar Subtitles puts the subtitles you already have onto any web video, then turns them into a colour-coded grammar lesson. IMPORTANT: this extension contains no videos and no subtitle content. You supply the subtitle files (.srt, .vtt, .ass) or import them from a public catalogue: kitsunekko.net for Japanese, or SubDL for English, Thai, Simplified Chinese and Traditional Chinese. It does not bypass DRM, unlock paid content, or host copyrighted material. The SubDL search uses your own SubDL API key; no key is bundled. SUBTITLES ON ANY VIDEO • Load one or two subtitle files (original + translation) onto a video, or drag them straight onto the page. • The subtitle layer is draggable and resizable; position, style and timing offset are saved per page path. • Timing offset is adjustable from the panel or with Alt+[ / Alt+] while the video has focus. • Show a translation for a limited time and let the original stay visible, so you read first and then listen. • Mark advertisement segments and skip them with a keyboard shortcut. COLOUR-CODED LANGUAGE PACKS • Japanese: part-of-speech colouring, optional furigana, JLPT N1–N5 word cards and sentence playback through your system's Japanese voices. • English and Thai: part-of-speech, phrase and syntax colouring with offline dictionary cards (English cards include IPA), tuned for contrast on bright and dark video. • Choose a study mode per language — original text, part of speech, syntax roles, phrase blocks, expressions or reading aids — and keep a separate palette for each. • Tokenisation and dictionary lookups run fully offline; the dictionaries ship with the package. SUBTITLE LIBRARY • Import individual files, whole folders, or a zip archive. Files are grouped into one pack per series. • Search the public kitsunekko.net index for Japanese, or SubDL for other subtitle languages, from the options page or the toolbar popup. SubDL requires your own API key. • Japanese or Chinese search terms are translated to English for the catalogue search (via Google's public translation endpoint). • Every pack records where it came from; re-importing a series merges into the existing pack. BUILT FOR DAILY USE • Toolbar popup for the current page, subtitle search, site rules and learning settings. • Light, dark and system themes; English and Simplified Chinese interface. • No account, no sign-in, no ads, no analytics. Your subtitle library stays in local extension storage. PRIVACY The extension reads pages only to find video elements, synchronise subtitles and restore per-page settings. Network requests happen only for the optional online subtitle import (kitsunekko.net, or SubDL with your own key), query translation and, if you enable it, an analysis server you configure yourself. Full policy: https://donespeak.github.io/visual-grammar-subtitles/privacy/. Not affiliated with Bilibili, kitsunekko.net, JMdict/EDRDG, or OpenMoji. Subtitle and dictionary credits are listed in the package's NOTICE files.