Dual Subtitles for YouTube™

YouTube向けバイリンガル字幕 — 原文と翻訳を重ねずに1つのレイヤーで表示。

Dual Subtitles for YouTube™ shows the original caption and a translation at the same time, as one clean layer — great for language learning and for following along in a second language. Official site: https://gythiro.github.io/yt-dual-subs/ FEATURES • Two languages, one set of lines. Original and translation appear together, and YouTube's own caption layer is hidden so the two don't sit on top of each other. • Whole sentences, not word by word. Lines are rendered from the caption's own timings and turn over by sentence. • Three ways to translate. By default it uses YouTube's own whole-track translation, which is aligned to the original. When a track cannot be translated, fragmented auto-captions are first rebuilt into full sentences and then translated — no word salad. Either engine can also be pinned by hand. • Or bring your own API key. Twelve providers, including DeepSeek, Gemini, DeepL and Alibaba Cloud Model Studio. With an LLM key each sentence is understood as a whole and then split back across the subtitles; DeepL is given the sentence as context for the same effect. The key is stored on your own machine and is sent to nobody but the provider you picked. This is entirely optional — the extension works with no account and no key. • 50 target languages, and you choose which ones appear in the popup menu. • Fully customizable. Per-line font, size, text colour, background colour and opacity, outline, line spacing, and which line sits on top — with a live preview. • Draggable and positionable. Drop the subtitle box anywhere on the video; it remembers where. Works in fullscreen. Double-click to reset. • One-click toggle. A caption button in the player's control bar turns the overlay on or off — handy for videos that already have burned-in subtitles. • Works on YouTube Shorts — bilingual subtitles on the vertical player too. • Export to SRT. Save the current video's subtitles for offline study — original, translation, or bilingual. If you have set up your own key, the export can go through it instead: it tells you how many requests that will take before it sends anything, and it is off by default. PRIVACY No accounts, no tracking, no analytics, no ads, and no developer server. Your settings stay in your browser. The only thing sent out is the caption text of the video you are watching, and it goes to the translation service in use — YouTube's own, Google Translate, or the provider whose key you supplied. Nothing is sent to the developer. Full policy: https://github.com/Gythiro/yt-dual-subs/blob/main/PRIVACY.md Open source (MIT): https://github.com/Gythiro/yt-dual-subs Not affiliated with, endorsed by, or sponsored by YouTube or Google LLC. "YouTube" is a trademark of Google LLC, used only to describe compatibility.