Quick demo of something we've been working on for a while: a Safari extension for iPhone that retunes audio in real time as it’s playing. So instead of hunting for a “432Hz version” of a song on Spotify, YouTube or Apple Music, you just play the original and the extension shifts the pitch live.

In the video you can see us switch between standard 440Hz tuning and 432Hz on a track that’s playing — no reload, no download, no separate player. It works on any audio Safari can play, so YouTube, YouTube music, Apple music and Spotify.  
You can also flip between the Solfeggio frequencies (396, 417, 528, 639, 741, 852, 963 Hz) or your own custom A4 Hz target if that’s what you’re into. The retuning is real pitch-shifting, not a placebo EQ — it’s the same core tech we patented and put in all of our real-time Solfeggio retuning apps.

A few things we get asked:  
	•	Can I keep listening in the background? Yes. You can minimize Safari while you listen!  
	•	Does it work in the native apps? No, Safari only — iOS doesn’t let extensions touch other apps’ audio.  
	•	Other browsers? For iPhones you can only use the Safari extension for now; for desktop in addition to Safari we have this available for Chrome, Brave, Edge, Firefox and Opera.

Happy to answer anything. If you want to try it, it’s part of the Retuner Pro lineup — link in the sub’s sidebar.

Retune any Spotify song to 432Hz on iPhone in real time — Safari extension demo