KaraFun vs Nightingale

KaraFun is a karaoke service for singing together, with singing battles and music quizzes on Android, iOS, macOS, web, and Windows. Its free plan includes free songs, Premium song previews, access to try features, and one quiz. Premium costs £7.99 a month and adds all songs, playlists, offline sync, unlimited quizzes and Battle, and remote connections for up to 20 people. Singers can adjust key and tempo and select lead, backing, or guide vocals; guests can browse the catalog on a smartphone and add songs to the queue. KaraFun says it adds more than 400 new karaoke songs each month. Offline Sync can keep up to 1,000 songs on a device. Vocal Match compares a user's voice with songs and is available only on iOS and Android. Premium is for private use; professional or public performances require a professional subscription. Pro costs £39.99 a month and includes a commercial license and sound recording rights coverage with synchronized lyrics for its licensed catalog. Public performance royalties remain the customer's responsibility. One account can be used on only one device at a time, though the app may be installed on multiple devices.

Nightingale turns songs from local folders or Plex Media Server, Jellyfin, and Navidrome libraries into karaoke tracks with separated vocals, synchronized lyrics, and real-time pitch scoring. Vocal separation uses the UVR Karaoke model or Demucs. WhisperX transcribes and aligns lyrics word by word, and LRCLIB lyrics are used when available. Japanese, Chinese, Cantonese, and Korean songs can use character-level alignment and romanized readings.

After analysis, users can adjust key and tempo and follow pitch scoring. Lyrics can be provided as timed LRC or Enhanced LRC, pasted as plain text for alignment, or edited. Playback backgrounds include 10 GPU shader options, five Pixabay video styles, and video files. The app supports MP4 and MKV videos and experimental UltraStar song folders. Multiple profiles keep separate score histories; navigation can use a gamepad or touch controls. Native Linux, macOS, and Windows builds use CUDA or Metal acceleration when available, with CPU fallback. A web build can run on a Linux computer on a home network and open in a browser. The app is free and open source under GPL-3.0-or-later, describes itself as having no cloud, and encrypts Navidrome login details on disk.