Tesla-inspired sound
Balance, tuned to Tesla's numbers.
3·6·9 is a binaural beat and tone player for relaxation and meditation. Pick Ground, Create or Calm, put on headphones, and let the sound do the rest.
Free to try · Works on iPhone and Android · No account needed
Please listen safely
- Never while driving or operating machinery or heavy equipment. These sounds are made to relax you and can cause drowsiness.
- Not near traffic. Don't wear headphones while walking or cycling, or anywhere you need to hear your surroundings.
- Seizures. If you have epilepsy or a history of seizures, talk to a doctor before using binaural or rhythmic audio.
- Keep the volume low to moderate. Stop if you feel dizzy or unwell.
- 3·6·9 is not a medical device and not a treatment for any condition. Not intended for young children.
"If you only knew the magnificence of the 3, 6 and 9, then you would have the key to the universe."Widely attributed to Nikola Tesla
Tesla was famously fascinated by these three numbers. 3·6·9 turns the idea into its structure: three binaural beats at 3, 6 and 9 Hz, and Solfeggio tones whose digits add up to 3, 6 or 9. For example, 528 → 5+2+8 = 15 → 1+5 = 6. It's an organizing idea and an inspiration, not a scientific claim.
Three presets, one idea
Each preset pairs a slow binaural beat with its own carrier tone, so you can choose the feel of a session in one tap.
Ground
3 Hz beat
Grounding and release. For winding down and settling the body.
Create
6 Hz beat
Meditative and creative. For loosening up and letting ideas drift.
Calm
9 Hz beat
Alert calm and completion. For staying settled without getting sleepy.
What's inside
Solfeggio tones
Seven traditional frequencies from 174 to 963 Hz, each with its own beat. Their descriptions come from Solfeggio tradition and folklore, not from science.
Journey builder
Chain presets and tones into a timed sequence that plays hands-free, with smooth crossfades between stages.
ADHD focus mode
A 16 Hz beta beat plus theta and alpha options, designed around early research on white noise and attention. The evidence is promising but mixed.
Soundscapes
Layer in rain, ocean, waves, white noise, or a quiet cello arrangement of Beethoven, and balance it against the beats.
Keeps playing
Audio continues when you switch apps or lock your screen, with play and pause on your lock screen.
Installs like an app
Add it to your home screen and it opens full-screen. The tones and soundscapes are generated on your device. The music track needs a connection.
Free to start, Premium to go deeper
The presets and soundscapes are free. Premium adds the rest. No account is needed, just a license key from your purchase.
Free
$0
- Ground, Create and Calm presets
- Rain, forest rain, ocean, waves, soft chord, white noise and the Beethoven cello
- Sleep timer and saved mixes
- Three quick sessions
- Practice stats, mood notes and a daily reminder
Premium
from $2.50 a month, billed yearly
- All seven Solfeggio tones in the Frequencies tab
- The Journey builder and the full session library
- ADHD focus mode
- Try it free for 7 days, no card needed
Yearly $29.99 · Monthly $4.99 · Lifetime $59 (pay once)
Prices are in US dollars; tax may be added at checkout. Payments are handled by Lemon Squeezy. Premium plans are opening soon, and until then every feature stays available. See the Terms and Privacy pages for details.
A look inside
How it works, honestly
A binaural beat happens when each ear hears a slightly different tone through headphones. Your brain perceives a slow pulse at the difference between them. 3·6·9 uses differences of 3, 6 and 9 Hz.
Many people find this kind of sound relaxing. Scientific evidence that binaural beats change mood or attention is early and mixed, and the app doesn't claim to treat or cure anything. Treat it as a relaxation and meditation tool, and see a professional for medical or mental health concerns.
You need headphones. Without separate left and right audio there is no binaural effect.
Install it on your phone
iPhone
- Open this site in Safari.
- Tap the Share button.
- Choose Add to Home Screen.
Android
- Open this site in Chrome.
- Tap the three-dot menu.
- Choose Install app or Add to Home screen.