Guide
Start with the thing in front of you
Lumi is a browser extension—a video learning companion you install in Chrome or Edge. Open a YouTube or Bilibili video and a Lumi card appears on the right, with live subtitles on the video itself.
Tip: Install the extension first, then keep this page open next to a video you are actually watching.
Install it and use it the first time
Add Lumi from the Chrome Web Store or Edge Add-ons, then pin it to the toolbar. Open any YouTube or Bilibili video and the panel appears on the right. Pick your interface language and subtitle target language when asked. Watching subtitles, searching, and styling work without signing in.
Go to downloadThe video has no subtitles
When the platform already has captions, Lumi uses them for contrast, translation, and cleaner line breaks. If there are none, run speech-to-text (ASR) first, then translate, summarize, and ask. Export SRT when you want to take the transcript with you.
See ASR packsSign in, or bring your own key
Both work. Sign in to use Lumi AI with included tokens. Or paste your own DeepSeek, OpenAI-compatible, Anthropic, or Gemini key in the extension settings and spend your own quota. Subtitle style and search do not require an account.
Sign in to LumiYou ran out of quota
Summaries, chat, articles, and translation on Lumi AI spend tokens. ASR spends duration. After that you can upgrade to Pro, buy a token or ASR pack, or switch to your own key. Signed-in users can see remaining quota on the account page.
View my quotaAsk while you watch, then jump back
Open chat on the video page and ask about the current moment. Answers carry timestamps you can click. Chapters and article paragraphs work the same way. Stay on the video instead of opening a new tab.
Where did the videos I studied go?
After you sign in, recent videos sync to the web workspace. Videos you add to the library can be searched later. Anonymous progress stays on this browser.
Open libraryThe Edge store build is behind
Store review can lag. Install the official manual package from the site. If you already have the store build, disable it first so you do not end up with two Lumi icons.
Install Edge manuallyFAQ
- Which languages does Lumi support?
- The interface supports Simplified Chinese, Traditional Chinese, English, Japanese, and Korean. Subtitle translation covers common study languages.
- Do I have to pay?
- No. Subtitles, search, and styling are free. AI can run on included tokens, your own key, or Pro.
- Will my watch history be sold?
- No. After sign-in we only sync the records and preferences you need to keep learning across devices. We do not sell them for ads.