Tuning fork
Play an A4 reference tone
Play an A4 reference tone to tune an instrument or check a pitch directly in the browser.
Tuning fork
A4
Quick explanation
Set the A4 frequency, adjust the volume, then start or stop the sound. The tuning fork generates a simple sine wave directly in the browser.
Try this too
Need to generate another frequency?
Use the frequency generator to create a pure tone at the frequency of your choice and download a WAV file.
Additional information
How to use the online tuning fork
Set the A4 frequency with the − and + buttons or by editing the displayed value directly. By default, the tuning fork uses A4 = 440 Hz, which is the most common reference.
Then adjust the volume and use the Play button to listen to the A4 tone.
What is a tuning fork used for?
A tuning fork produces a reference pitch. It can be used to tune an instrument, check a note, or quickly get a stable A4 tone.
In this tool, the sound is generated as a sine wave, which gives a simple, clear, and lightweight signal.
A4 and reference frequency
A4 at 440 Hz is a widely used tuning reference. It means that the A4 note corresponds to 440 vibrations per second.
The frequency can be changed between 300 Hz and 500 Hz to test or use another reference, such as a slightly lower or higher A4.
Sound generated in the browser
The sound is produced directly by the browser with Web Audio. It is not an external audio file and not a system MIDI sound.
This keeps the tool lightweight: no audio file is loaded and no server-side processing is needed to produce the sound.
Tuning fork or note frequency?
The tuning fork is designed to quickly listen to an A4 reference tone. To calculate the frequency of other notes or understand the relationship between note, octave, and frequency, use the note frequency tool.
Data and privacy
The sound and settings are handled directly in the browser. The selected frequency and volume are not sent to the server to use the tool.
Limits and reuse
AppErgo tools are provided free of charge for practical and informational purposes. Although care is taken in their design, a result may be incomplete, unexpected or incorrect. Before relying on a result for any important use, check it using an appropriate method.
To report a bug in the tool, you can use the dedicated bug report form.
Results produced by AppErgo tools may be copied and reused freely. When publicly reusing a result, a method or an AppErgo page, a link to the relevant page is appreciated.
Unless otherwise stated, AppErgo texts, images, visual elements, scripts, templates and internal components remain the property of AppErgo.
For any other request, you can contact the webmaster.