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Frequency to Note

Convert between Hz frequencies and musical note names in both directions.

Exact note frequency440.00 Hz

MIDI note number69

Cents deviation0.0 cents

Octave:

440.00

Note nameA4

MIDI note number69

About Frequency to Note

Frequency to Note is a free browser-based audio tool that lets you convert between hz frequencies and musical note names in both directions without installing any software. Musicians, podcasters, sound designers, and hobbyists use this tool for quick audio tasks directly in the browser. All audio processing happens locally using the Web Audio API — nothing is uploaded to any server.

How to Use

Load your audio Upload an audio file, record from your microphone, or use the built-in controls to get started.

Adjust settings Use the available controls to set parameters like frequency, tempo, volume, or effect type.

Listen and adjust Preview the audio output and fine-tune settings until you're satisfied with the result.

Save or export Download the audio output or copy any generated data for use in your project.

🔒 Privacy note: All processing happens locally in your browser. Your data is never sent to any server.

Why Use Frequency to Note?

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Browser-Based Audio Frequency to Note uses the Web Audio API for high-quality audio processing directly in your browser. No plugins, no downloads — just open and start.

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Your Audio Stays Private Audio files and recordings are processed locally on your device. Nothing is uploaded to any server or stored anywhere.

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Professional Features Get capabilities that traditionally required desktop software like Audacity or FL Studio, accessible instantly from any browser.

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Works on Any Device Fully responsive design and touch-friendly controls make it easy to use Frequency to Note on desktop, tablet, or smartphone.

Frequently Asked Questions

A cent is 1/100th of a semitone. If a frequency is exactly on a note, deviation is 0 cents. If it is halfway between two notes, deviation is ±50 cents. This is useful for checking how in-tune an instrument is.

440 Hz was adopted as the international standard pitch by ISO in 1955. Before this, concert pitch varied between orchestras. Some orchestras tune slightly higher (442–445 Hz) for a brighter sound.

MIDI note = round(12 × log₂(freq / 440) + 69). The inverse gives Hz from MIDI: Hz = 440 × 2^((midi − 69) / 12). Cents = 1200 × log₂(freq / noteHz).