When you use the Online Pitch Detector on OnlinePitchDetector.com, your microphone audio is captured locally in your browser, analysed to detect the fundamental frequency of the sound you produce, and then discarded. It is never recorded. It is never stored. It is never transmitted to any server. What you play or sing during a detection session never leaves your device.
This page documents exactly how that works.
How the Microphone Pipeline Works
The Online Pitch Detector uses your microphone as a pitch measurement instrument. The entire pipeline — from permission prompt to result display — occurs within your browser with no network activity at any stage.
Stage 1 — Permission prompt The browser displays a microphone permission prompt before any audio is accessed. OnlinePitchDetector.com cannot access your microphone without your explicit approval. If you decline, no audio is accessed and the tool does not run.
Stage 2 — Local audio stream Once permission is granted, the browser opens a live MediaStream from your microphone using the getUserMedia() API. This stream exists only in your browser’s active memory. It is not routed to any external server, not logged by any analytics or advertising tool, and not written to any browser cache or persistent storage.
Stage 3 — Web Audio API processing The microphone stream connects to a MediaStreamAudioSourceNode within an AudioContext, then feeds into an AnalyserNode for FFT analysis. The time-domain audio buffer is simultaneously passed to the YIN autocorrelation pipeline for fundamental frequency detection. All processing occurs entirely within the browser’s local audio graph. No audio data exits this graph.
Stage 4 — F0 detection and result display The YIN algorithm identifies the fundamental frequency from the local audio buffer. The result — Hz value, note name, cents deviation — is what appears on screen. The audio frames that produced it are not retained. No recording, no waveform snapshot, and no spectral data is stored or transmitted.
Stage 5 — Session clear When you close or reload the tab, the MediaStream is closed, the AudioContext is suspended, and all in-memory audio buffers are released. There is no persistent copy of your audio anywhere after this point.
What This Site Never Does With Your Audio
- Never records your audio to any file, database, or storage medium
- Never transmits audio over the internet to any server, including this site’s own server
- Never shares audio with Google Analytics, advertising networks, or any third-party service
- Never stores audio in browser localStorage, sessionStorage, IndexedDB, or cookies
- Never retains audio after the detection session ends or the tab is closed
- Never uses your audio for any purpose other than displaying the real-time pitch reading on screen
- Never accesses the microphone without displaying the browser’s permission prompt first
Your Musical Performance Is Private
For musicians using this tool during practice, rehearsal, or composition: the local-only architecture means your playing never reaches a server. There is no cloud processing step. There is no audio logging. The pitch detection happens on your device using your browser’s local JavaScript and Web Audio API — and is cleared when the session ends. You can practise, test intonation, and explore pitch freely without any audio data being collected.
Advertising and Analytics Are Separate From Your Audio
OnlinePitchDetector.com does not currently run advertising. If basic analytics tools are present on this site, they operate entirely separately from the Web Audio API pipeline. Analytics collect anonymous page-level data — page views, browser type, approximate region — through standard HTTP request metadata. They have no access to the Web Audio API, no access to the MediaStream, and no ability to interact with audio in any form.
The microphone permission you grant to this site is scoped to the Web Audio API pitch detection pipeline only. It does not extend to any other script or service on the page.
File Uploads
The Online Pitch Detector does not involve file uploads of any kind. No audio files are uploaded to any server as part of using this tool. The only audio data processed is the live microphone stream handled locally as described above.
HTTPS Encryption
All pages on OnlinePitchDetector.com are served over HTTPS. All data exchanged between your browser and this site’s server — page content, scripts, and voluntary contact form submissions — is encrypted in transit. Audio data never travels over the network and therefore requires no network-level encryption.
Cookies and Session Data
Your pitch detection readings are displayed on screen during your session only. They are not written to cookies, not stored in localStorage, and not sent to any server. Closing or reloading the page clears all session data entirely. For a full explanation of what cookies this site uses, see the Cookie Policy.
Children’s Privacy
OnlinePitchDetector.com does not knowingly collect personal data from children under the age of 13. The tool requires no account registration and requests no personal information. Audio is never transmitted or stored for any user. If you believe a child has submitted personal data through the contact form, contact Vincent Sullivan at contact@onlinepitchdetector.com and the data will be deleted promptly.
Reporting a Security Concern
If you identify a potential security vulnerability on OnlinePitchDetector.com — including any behaviour suggesting audio or user data is being handled contrary to what is documented on this page — report it immediately via the Contact page with the subject line “Security Concern.” Vincent Sullivan reviews all security reports personally within 48 hours.
Your Privacy Rights
Your rights regarding any personal data this site may hold are documented in full on the Privacy Policy and GDPR and CCPA pages.
Written by Vincent Sullivan, founder of OnlinePitchDetector.com. Last updated: June 2026.