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Music-oriented YouTube web-app - single-page, client-side, simple
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A simple YouTube Web-App focussed on music playback (aka small project that my subconcious thought up to prevent myself from learning for pesky exams)

  • Free, easy to modify and all important stuff happens client-side
  • No official YouTube API used
  • No third party code used (yes, not even a media player)
  • Only 30kb (download) / 110kb (memory) - much smaller than YouTube and even Invidious
  • Standard player features (select streams freely, e.g. audio only)
  • No arbitrary restrictions (e.g. background playback on mobile)
  • Prooven interface including dark and light theme
  • Basic settings
  • Save and cache playlists in local database
  • Watch page including:
    • Comments and Threads
    • Related videos (excluding mixes and livestreams for now)
    • Playlists large and small
  • Search (videos only) with filtering by category
  • Channel page including all tabs

Missing standard features

  • Home Page
  • Subscriptions / Feeds
  • Subtitles
  • Download Button
  • Proper synchronized DASH playback with MediaSourceExtension
  • Playlist/Channel search

Future aspirations

  • Separate Database Management Site:
    • Multi-dimensional graphs showing correlation between videos (based on metadata or even media analysis)
    • Advanced playback filtering based on tags and corresponding weights (e.g. favour a specific genre)
    • Set operations on playlists (e.g. all music minus my favourites and music older than 5 months)
  • Playlists including local media (or replace youtube streams with higher quality local media)
  • Experiments to extract metadata (like lyrics) from description and/or comments or from wikis/databases
  • Next-up queue overriding current playlist
  • Related videos browser - dive into related videos of related videos (could work great with next-up queue)

Known Issues

  • Video Playback, especially high resolutions, are super laggy and quickly go out of sync. Proper MSE implemenentation is needed AND local CORS server, since MSE would force all streams to be routed through a CORS server
  • Wrong aspect of thumbnails for videos with 1. only low resolution thumbnail AND 2. non 16-9 ratio - pretty rare
  • Current video title is original (not translated), while related videos, etc. are all translated
  • Most video titles are translated... (there's hope though)

How To Use


Local Project:

  1. Download the project (master)
  2. Select a public CORS host (see /page/page.js, l.205 below HOST_CORS) or set up your own (see below)
  3. Load up /page/index.html
  4. Open the settings in FlagPlayer (gear top right)
  5. Set the CORS host field to your selected CORS host (default is restricted to official website)
  6. Search for videos or enter a playlist id in the search bar

Local CORS Server:

  1. Download the project (master)
  2. Install node.js
  3. On Windows: Execute /server/CorsServer.bat
  4. On Linux: Execute /server/
  5. Note your local server adress as displayed in the console, usually http://localhost:8080
  6. Open the settings in FlagPlayer (gear top right)
  7. Enter local server adress into the Cors Server field
  8. Reload page and enjoy comments

Note: You need to start it every time OR set it up as a service
You can also copy the .bat/.sh and put it on your desktop - just edit it to point to the yt-server.js file


Why a separate server?

Direct request from one website to another website are usually blocked by the browser itself according to the CORS prolicy to prevent XSRF. For any website scraping other website's content that means a reverse-proxy needs to be set up so that the CORS policy doesn't block the request.

How does media playback work?

YouTube uses something calles MSE to exactly control the behaviour of buffering (loading) - since that means all request are script-controlled, all media fetch requests would now fall under the CORS policy and would have to be proxied. Since that would add immense load on public servers, I've chosen to make a hacky replacement to support DASH streams (where audio and video is separated), which works for most videos up to 2k. Additionally, the legacy streams (audio and video combined, only up to 720p) are supported as well.
This does however mean that buffering, etc. is still handled by the browser, and it subject to it's whims and bugs. Sometimes, a promise to start a stream will never resolve (Chrome), and the stream has to be restarted, resulting in audio glitches. Sometimes, the browser might arbitrarily decide to lower the buffering size, effectively preventing preload of anything more than 2s of video - especially a problem on low-bandwidth networks.


  • YouTube is terribly bloated and loads embarassingly slow
  • YouTube has several bugs hindering effective playback
  • YouTube forces streaming of video - even if you only use audio
  • YouTube doesn't allow background music playback on mobile
  • Music Playback pf mixed content (local + YouTube) is difficult
  • I wanted a cross-platform music player to do experiments on
  • I wanted to do a more complex webpage
  • YouTube is terribly bloa- ah.


The project is licensed under the AGPLv3 license - see the license file for details. I'd appreciate a sensible usage.

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