Best AI tool to summarize YouTube videos on my Windows laptop?

This one is for you if you want to keep everything completely off the cloud and don't mind a bit of setup. OpenBrief is an open-source desktop app that is essentially a private, local version of NotebookLM.

How it works: You paste a YouTube link into OpenBrief. It uses a built-in tool (ytdlp) to download the video locally, then runs Whisper (a transcription engine) on your own computer to convert the audio to text. Finally, it sends that transcript to an AI to generate a "grounded" summary with clickable timestamps.

To summarize YouTube video with AI tool:

Step 1: Paste the link

Step 2: It downloads the video locally

Behind the scenes, OpenBrief uses something called ytdlp to grab the audio from that video and save it right onto your hard drive . No streaming, no buffering—the file lives on your machine.

Step 3: Transcription happens on your device

This is where OpenBrief gets interesting. Instead of sending your video to some cloud server for transcription, it runs Whi sper locally on your computer. The audio gets converted to text with timestamps, and none of it ever leaves your PC.

Step 4: AI generates a "grounded" summary