Blind self-test — can you really tell?
The honest way to explore the lore: this plays two short tones in random order — the selected frequency and a control shifted by the amount you choose. Guess which was the real one. If your score hovers near 50% over many rounds, you can't reliably tell them apart — and that's a real, useful finding.
Frequently asked questions
What are the Solfeggio frequencies?
A set of nine tones — 174, 285, 396, 417, 528, 639, 741, 852 and 963 Hz — each carrying a traditional label such as "releasing fear" (396 Hz) or "transformation" (528 Hz). The modern set was assembled in the 1970s by Joseph Puleo and popularized in 1999 by Leonard Horowitz. They're often described as ancient Gregorian chant tones, though historians dispute that origin story. This player generates all nine exactly, plus the 432 Hz alternative tuning and the 40 Hz gamma frequency.
Do they work? What does science say?
Sound genuinely affects us — that part is solid science. Music and steady, gentle tones measurably reduce stress and anxiety, calm heart rate, lift mood, and help with sleep onset and focus. Music therapy is an established clinical field, and relaxing to calming sound is one of the best-supported wellness practices there is. The 40 Hz gamma frequency included here is also the subject of serious ongoing neuroscience research.
What's not established is the specific lore: there's no credible evidence that one particular number — 528 Hz or any other — heals the body or "repairs DNA," and we won't pretend otherwise.
The good news: you don't need magic numbers. If a quiet 528 Hz tone helps you unwind, that benefit is real, yours, and backed by everything we know about sound and the nervous system. The traditional labels are a beautiful piece of musical folklore to explore in exactly that spirit — at a comfortable volume.
What's special about 528 Hz?
528 Hz is the most famous Solfeggio tone — nicknamed the "love frequency" or "miracle tone," with lore claiming it repairs DNA. That specific claim has no biological evidence behind it. Musically it sits close to the note C5, and many people find it a genuinely pleasant, calming tone — which is a perfectly good reason to play it.
Binaural beats vs. pulse mode — what's the difference?
Binaural beats play a slightly different frequency in each ear; your brain perceives the difference as a slow beat. They require stereo headphones. Pulse (AM) mode rhythmically varies the loudness of a single tone instead, so it works on any speaker. Both modes let you set beat rates across the delta, theta, alpha, beta and gamma ranges, up to 40 Hz.
Is this player free and private?
Yes. Completely free, no account, no ads. Tones are synthesized locally in your browser with the Web Audio API — no audio is recorded, uploaded or stored. The site uses Cloudflare's cookieless, privacy-first analytics to count visits: no cookies, no personal profiles.
Can I use it for sleep or meditation?
That's what it's best at. Use the auto-stop timer (5–60 minutes) or the journey mode that moves through all nine tones automatically. Keep the volume low and comfortable — quiet tones are just as effective for relaxation, and loud sustained tones can fatigue your ears.
Can I install it as an app?
Yes. On Android Chrome, choose Install app from the browser menu; on iPhone/iPad Safari, tap Share → Add to Home Screen. It opens full-screen like a native app, keeps your settings and theme, and works fully offline — the tones are generated on your device.