Build a personal knowledge base from YouTube videos

Most of what we learn from YouTube is gone within a week. You remember that a video explained something well, but not which video or where in it. A small knowledge base fixes that: one place where each useful video has a summary, the points you cared about, and a link back to the exact moment.

What a video knowledge base needs

1. A summary per video, so you can tell months later what it covered.
2. The points you actually care about, saved separately from the full summary.
3. A link to the source moment for every point, so you can check it instead of trusting your memory.
4. A regular review, or the library turns into a graveyard.

How to build one with sum.video

Step 1: summarize as you watch

Paste the link on sum.video or click Summarize in the Chrome extension next to the player. You get key insights with timestamps, the full transcript and a chat. The summary is saved to your account.

Step 2: save the points worth keeping

Open the save menu on a point and add it to a Wisdom collection. Free accounts save to a default collection; Pro lets you create named collections such as "Sales calls", "Machine learning course" or "Recipes".

Step 3: review with the Sunday recap

Every week sum.video can put together a Sunday recap: up to seven points from the videos you summarized that week, each linking back to its summary. Five minutes on Sunday is enough to decide what to keep.

Step 4: go back to the source

When you need an idea again, open the saved point, read its summary, and click the timestamp. If you need the exact words, search the transcript. See search YouTube transcripts.

Why saving points beats saving whole videos

Bookmarking a video saves the container, not the idea. Writing the idea down is what helps you keep it: in a well-known set of experiments, students who took notes by hand, and had to put ideas in their own words, did better on conceptual questions than students who typed lectures word for word (Mueller and Oppenheimer, 2014). A later replication found the difference smaller and less consistent than first reported (Morehead, Dunlosky and Rawson, 2019), so treat it as a nudge to put ideas in your own words, not as a rule about pens.

A summary is a starting point, not a replacement for that step. The same applies to AI help in general: in a 2025 experiment on note-taking from lecture videos, moderate AI support led to the best test scores and fully automated notes to the worst (Chen et al., 2025). Use the summary to find what matters, then save the few points you would explain to someone else.

A simple structure that lasts

• One collection per project or subject, not per channel.
• Three points per video at most. If everything is saved, nothing stands out.
• Rewrite a point in one line in your notes app when it really matters.

Using it with other tools

sum.video has no direct Notion or Obsidian sync. Copy the summary or transcript text and paste it into your notes. You can also ask about a video from ChatGPT or Claude with the sum.video connector.

For study-specific tips, see summarize YouTube lectures for studying and summarize videos to notes.

Sources

• Mueller and Oppenheimer, The Pen Is Mightier Than the Keyboard, Psychological Science, 2014
• Morehead, Dunlosky and Rawson, How Much Mightier Is the Pen Than the Keyboard for Note-Taking?, Educational Psychology Review, 2019
• Chen, Ruan, Ju, Yap, Wang, More AI Assistance Reduces Cognitive Engagement, 2025