Binaural Playground is a lightweight, web-based tool designed for exploring and creating custom binaural beat sequences. By playing slightly different frequencies in each ear, it generates the perception of a third tone (the binaural beat) to encourage various states of mind.
- 🔗 Instant URL Sharing: Every sequence you create is automatically encoded and appended to the URL hash. You can bookmark or copy the URL to easily save and share your customized sounds with others.
- 💾 Smart Persistence on Refresh: Never lose your progress. The app automatically saves your current sequence to your browser's local storage, ensuring it reloads exactly where you left off if you accidentally close the tab.
- 📱 Installable PWA (Progressive Web App): You can install Binaural Playground directly to your mobile home screen or desktop application list for quick access. It includes offline support thanks to a background service worker.
- 🌓 Adaptive Dark & Light Themes: The interface seamlessly responds to your system's light or dark mode preferences with a clean glassmorphic UI.
- 🎵 Custom Linear Transitions: Type in sequences to shift frequencies linearly between custom steps, allowing for a highly dynamic listening experience.
- 🔁 Loop Control: Toggle the Loop sequence checkbox to automatically restart your sequence once it reaches the final timestamp.
To build a sequence, enter your desired steps into the text box. Each line represents a point in time and must contain exactly 3 whole numbers separated by commas:
[Timestamp in milliseconds], [Left frequency in Hz], [Right frequency in Hz]
Example Sequence:
0,40,48
5000,240,248
In this example, the sound will start at 40 Hz (left) and 48 Hz (right), then transition smoothly to 240 Hz and 248 Hz over the course of 5 seconds (5000 milliseconds).
The difference between the left and right channel frequencies is the binaural beat frequency you experience:
- 1–4 Hz: Delta (Deep sleep)
- 4–8 Hz: Theta (Meditation / REM sleep)
- 8–14 Hz: Alpha (Relaxation)
- 14–30 Hz: Beta (Focus / Energy)
- 30–100 Hz: Gamma (Maximum Awareness)
Copy and paste these into the sequence box to get started:
Starts with a gentle Alpha relaxer and slides down into a deep Theta state over one minute.
0,200,210
30000,200,207
60000,200,204
A steady 15 Hz beat designed to help maintain alertness and concentration.
0,150,165
10000,150,165
A long, slow transition from waking frequencies down to deep Delta sleep.
0,100,110
120000,100,102
A high-frequency sequence intended for peak cognitive processing.
0,400,440
5000,400,440
Since this project uses a Service Worker for the Progressive Web App functionality, it needs to be served from a local web server (rather than opened directly as a local file).
You can spin up a quick server using Python:
# For Python 3
python -m http.server 8000Then open http://localhost:8000 in your web browser.
This project is licensed under the GPL v3 License. See the LICENSE file for full details.