Summaries, documents & PDF · 4 tools compared
Last verified:
Prices may changeStudent, free
Glasp ✓Free
The extension is free, and summaries use your existing ChatGPT or Claude account. No extra cost for videos with captions.
Korean first
Lilys AI ◐Free plan
Provides the cleanest Korean timeline summaries and summarizes uncaptioned videos via voice recognition.
Combine multiple videos and materials
Gemini Notebook ◐Free plan
Add YouTube links alongside PDFs and web pages in one notebook to ask questions with citations.
Right in the browser, multi-model
Sider ₩Paid
Summarize right in the YouTube sidebar and ask follow-up questions using GPT, Claude, or Gemini.
| Item | Lilys AI | Glasp | Gemini Notebook | Sider |
|---|---|---|---|---|
| Price | ◐Free plan | ✓Free | ◐Free plan | ₩Paid |
| Free limits | Unlimited AI reports and chats. Supports YouTube, video files, PDFs, and web pages. | The extension itself is free. Summaries run through your own ChatGPT or Claude account. | Free with a Google account. Limits on number of notebooks, sources, and daily queries. | No free tier |
| Paid price | Starter ₩6,320/month · Basic ₩15,920/month · Pro ₩51,120/month (billed annually) | None | Higher limits included with Google AI Pro subscription | Lite $25/month · Pro $50/month · Max $100/month (17% off for annual billing) |
| Korean | ○KoreanKorean service. Both UI and summaries default to Korean. | △PartialThe UI is in English. Videos with Korean subtitles can be summarized (requires subtitles to be available). | ○KoreanSupports Korean sources, questions, and answers. Audio Overview (podcast) supports Korean. | ○KoreanBoth UI and summaries are in Korean. YouTube subtitle summaries are also provided in Korean. |
| Login | Required | Optional | Required | Required |
| Platforms | Web · iOS · Android · Browser extension | Browser extension · Web | Web · iOS · Android | Web · Browser extension · iOS · Android · Windows · macOS |
| Videos without Captions | Supported (Speech recognition) | Not supported (Captions required) | Captioned videos only | Mainly for captioned videos |
| Timeline Summary | Chapter summaries + Timestamp jump | Transcript timestamps only | None (Q&A format) | Partial chapter summaries |
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Lilys AI generates Korean summaries and clickable timestamped chapters from YouTube links. It works even on videos without captions using speech recognition. The UI is entirely in Korean. The free plan limits monthly summaries and video length, so heavy users may need to upgrade.
Glasp's extension extracts transcripts and sends them to ChatGPT or Claude. The extension is free, using your existing AI account for summaries with no added cost. However, it cannot summarize videos without captions, and the English-only interface takes some initial setup.
NotebookLM lets you add YouTube links as sources. It is best for combining multiple lecture videos, PDFs, and web pages in one notebook to ask cross-source questions with citations. It is free with generous limits, but lacks timeline summaries and requires video captions.
Sider is a browser sidebar extension that summarizes videos instantly on YouTube. You can ask follow-up questions using GPT, Claude, or Gemini. It supports Korean UI and summaries. With no free tier, paid plans start at $25/month, covering YouTube, web pages, and PDFs.
Consider four factors: First, support for videos without captions via speech recognition. Second, timeline navigation for long lectures. Third, pricing structure (standalone limits vs. using existing AI accounts). Fourth, follow-up workflow (simple reading, multi-source Q&A, or in-browser chat). Always respect creator copyright.
| Situation | Pick | Why |
|---|---|---|
| 🎒 Student, free | Glasp | The extension is free, and summaries use your existing ChatGPT or Claude account. No extra cost for videos with captions. |
| 🗣️ Korean first | Lilys AI | Provides the cleanest Korean timeline summaries and summarizes uncaptioned videos via voice recognition. |
| 📎 Combine multiple videos and materials | Gemini Notebook | Add YouTube links alongside PDFs and web pages in one notebook to ask questions with citations. |
| 💼 Right in the browser, multi-model | Sider | Summarize right in the YouTube sidebar and ask follow-up questions using GPT, Claude, or Gemini. |
Not a ranking. Different situations, different answers.
Last verified:
Prices may change; confirm on each official site before paying. A comparison's verified date is the oldest of the comparison and its tools.
A Korean service summarizing videos, PDFs, and web posts in Korean.
A free extension that sends YouTube transcripts to ChatGPT for summaries
A research notebook that answers only from your files with citations
A browser extension to summarize and translate any webpage from the sidebar