How to organize videos to know what each one is almost instantly without playing video?

For a local YouTube archive, I would not rely on one thing. Use three layers: Filename: keep title, channel, date, and video id. If you use yt-dlp, save the .info.json too. The video id is useful when titles change. Visual scan: create a contact sheet for each video. A grid of 12-20 frames usually tells you what the video is without opening it. You can do this with ffmpeg or a “video contact sheet” tool. Put the image next to the video with the same base name. Searchable text: keep subtitles/transcripts when available. If there are no captions, run a local transcription tool and save a short .txt summary beside the video. Then your folder has: video.mp4 video.jpg <- contact sheet video.txt <- transcript or summary video.info.json That gives you fast visual browsing plus normal file search. The contact sheet is the biggest win; transcripts are the second biggest if you remember topics but not thumbnails.