Free Online Audio Spectrum Analyzer
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About the Spectrum Analyzer
See a real-time frequency spectrum of any sound from your microphone — bar or line FFT view, all processed in your browser via Web Audio API with no upload.
How to use the Spectrum Analyzer
- 1Click Start and allow microphone access when the browser prompts.
- 2Speak, play music or make sound near your microphone.
- 3Watch the frequency spectrum update in real time.
- 4Switch between Bar and Line views, or toggle the log frequency scale.
Frequently asked questions
What is a frequency spectrum?
A frequency spectrum shows how much energy is present at each frequency in a sound. Low frequencies (bass) appear on the left; high frequencies (treble) appear on the right. The height of each bar indicates the loudness at that frequency.
What FFT size does this use?
The tool uses a 2048-point FFT by default, giving 1024 frequency bins. This balances frequency resolution with update speed.
Is my audio recorded or uploaded?
No — microphone audio is processed locally in your browser using the Web Audio API. It is never recorded, stored or sent anywhere.
Why do I need to grant microphone permission?
The Web Audio API requires explicit user permission to access the microphone. Permissions are per-session and can be revoked at any time in your browser settings.