Shiberu

Learn languages from media you watch and read.

Learn a language from the shows and videos you already watch. Shiberu turns subtitles into interactive, clickable text. Watch normally — then click any word you don't know to see its reading, part of speech, dictionary meaning, and an AI explanation of what it means in that specific sentence. One click saves the whole line — sentence, translation, reading, a screenshot of the scene, and audio — as a flashcard in your Shiberu account, ready to review with proven FSRS-6 spaced repetition. INTERACTIVE SUBTITLES • Every word is clickable and color-coded by how well you know it (Unknown / Learning / Known / Ignored). Words you know fade to plain text, so a sentence you've mastered reads clean. • Dual subtitles (target + native language), auto-pause at the end of each line, replay-the-line hotkeys, fine speed control, and furigana / pinyin for Japanese, Chinese, and Korean. AI IN-CONTEXT EXPLANATIONS • Not just a dictionary gloss — a short explanation of what the word means in this sentence, its register, and the grammar at work. Runs on Shiberu's own servers, so it's a free-tier feature, not a metered add-on. ONE-CLICK FLASHCARD MINING • Save any subtitle line as a rich flashcard: sentence, translation, reading, scene screenshot, and audio. Cards sync to the Shiberu app, where you review them with FSRS-6 spaced repetition. WORKS WHERE YOU ALREADY WATCH • YouTube, Netflix, Bilibili, and Viki, plus local video files and drag-and-drop subtitle files (.srt / .ass / .vtt). ONE PROGRESS GRAPH • Reviewing a card in the app promotes the word's status in the extension, and mining a word marks it as "learning." One vocabulary graph across everything you watch and study. PRIVACY • Shiberu only reads subtitle text — never the protected video or audio stream. • Subtitle text sent for analysis is cached anonymously and shared across users by the text of the line alone, with no account data attached. • AI explanations and text-to-speech run on Shiberu's own self-hosted models — your subtitle text is never sent to a third-party AI provider. • Shiberu does not sell your data and runs no remote or obfuscated code. • Full policy: https://shiberu.app/privacy/extension A free Shiberu account is required to save cards and sync your progress.