Tuning Fork
A tuning fork is a two-pronged steel fork that rings at one pure, steady pitch when struck. This online tuning fork plays that pure tone: A = 440 Hz by default, common forks like 432, 256 and 512 Hz, or any frequency you type in.
Plays a pure sine tone for 8 seconds, like a struck tuning fork. Turn your volume up gradually. No sound on an iPhone? Turn off silent mode.
- What it does
- Plays a pure sine tone at A 440 Hz or any frequency from 20 to 4000 Hz for 8 seconds
- What it does not do
- Use the microphone · check your instrument (use the online tuner)
- Reference pitch
- A4 = 440 Hz, adjustable 415–466 Hz
- Sound
- Generated in your browser with the Web Audio API
- Made by
- The Appcellent team
- Updated
- November 2026
Common tuning fork frequencies
| Fork | Frequency | Used for |
|---|---|---|
| A | 440 Hz | Standard concert pitch for tuning instruments |
| A | 442 Hz | Concert pitch used by some orchestras |
| A | 432 Hz | Alternative tuning some musicians prefer |
| C | 256 / 512 Hz | Scientific pitch forks (C4 = 256 Hz, C5 = 512 Hz) |
How a tuning fork works
When the prongs are struck they vibrate toward and away from each other at a fixed rate set by their length and thickness. The sound is almost a pure sine wave, with very few overtones, which makes it easy to compare against another note. That purity is also what this page plays.
To check an instrument against a fork, use the online tuner — it shows the difference in cents directly.