YouTube and web pages

NanumPlayer can play online videos with the same speech recognition, translation, glossary and style as local files. The picture and sound play in NanumPlayer, and subtitles are drawn by NanumPlayer, not on top of the website.

Both features use a small built-in browser window (Microsoft WebView2, normally already installed on Windows 11) provided by nanum_youtube.exe.

YouTube

1. Press Ctrl+Y or choose YouTube on the start screen. A YouTube window opens.
2. Browse and sign in as you normally would. Sign-in is optional and only needed for videos that require it.
3. Pick a video. NanumPlayer plays it using the window’s session through yt-dlp, and AI subtitles start as usual.

• First use: the YouTube tools (yt-dlp and Deno) are downloaded on demand, either from the installer’s optional tasks or from Ctrl+N → YouTube. Downloads are checked against a size and SHA-256 and update checks are offered; there is a cancel button.
• Paste an address: Ctrl+N → Play from a YouTube address… plays a copied link directly.
• Browser bookmark: an Open in NanumPlayer bookmark uses the nanumplayer://open?url= link that the installer registers.
• Subtitles: if the video has uploader-provided subtitles, they are used as the source text instead of speech recognition (you can switch to speech recognition in the menu). Auto-generated YouTube captions are not requested.
• YouTube may ask for extra checks or limit access when sign-in is used through unofficial tools. Respect YouTube’s terms of service.

Web page videos

For videos on ordinary sites:

1. Choose Play from a web page on the start screen, press Ctrl+Shift+Y, or use Ctrl+N → Play from a web page video address…, and paste the page address.
2. In the window that opens, sign in if the site needs it, and start playing the video on the page.
3. Click Play in NanumPlayer at the top. NanumPlayer takes over playback and AI subtitles.

NanumPlayer detects the real media address the page loaded, including videos inside iframes and HLS or DASH streams. Cookies, Referer and User-Agent for that video apply to that file only and do not carry over to the next one. Audio without a language tag starts with multilingual language detection, so install a multilingual speech model.

What does not work

• DRM-protected video.
• Sites that never expose a playable media or manifest address.
• Servers that refuse playback outside the browser. An address that expires has to be reloaded from the page.

Playback of every site is not guaranteed.

Nothing is kept

YouTube and web windows always run as InPrivate sessions. Sign-ins and cookies live only for that session and are removed with the browser’s temporary data when the session ends. General web cookies are passed to the player in memory; YouTube cookies use only a temporary file that is deleted at the end of the session. Use Ctrl+N → YouTube → End web session (sign out) to end it at any time.

Caution

InPrivate mode is not anonymity. Websites, your network, and the translation provider can still see what they can see, and the operating system may page memory or keep deleted files recoverable. See Privacy.

Web videos are never saved to the subtitle library, and a whole-file translation of a web video always goes to a temporary folder.