Written by Vincent Sullivan | Last updated: June 2026
Educational Purpose
OnlinePitchDetector.com and all content published on it — including the Online Pitch Detector tool, technical articles, explainers, FAQs, and supporting pages — is provided for educational and informational purposes only.
The information on this site is intended to help musicians, developers, and students measure fundamental frequency, understand pitch detection technology, and develop their knowledge of acoustic pitch science and equal temperament mathematics. It is not intended as professional audio engineering services, professional music instruction, clinical audiology services, or any other form of certified professional service.
Vincent Sullivan is an audio signal processing educator who has built this site to share accurate, technically grounded information about pitch detection. The content on OnlinePitchDetector.com reflects Vincent’s research and expertise. It does not constitute a professional engagement, and no professional relationship is created between Vincent Sullivan and any user of this site.
Pitch Detection Accuracy and Limitations
The Online Pitch Detector uses YIN autocorrelation-based fundamental frequency detection within the browser’s Web Audio API environment. The following limitations apply to every result produced by this tool.
Practical accuracy is ±2–5 cents, not sub-cent precision. Under typical conditions — a quiet environment, a sustained monophonic tone, a functional consumer microphone, and OS audio processing disabled — the tool achieves F0 detection accuracy of approximately ±2–5 cents in the range of 100–800 Hz. This is not the sub-cent accuracy achievable with professional hardware tuners and calibrated measurement microphones. For frequencies below 100 Hz, accuracy may be ±5–15 cents due to consumer microphone low-frequency roll-off.
Octave errors are an inherent limitation of autocorrelation-based detection. The YIN algorithm reduces but does not eliminate the tendency of autocorrelation-based detectors to return F0 at half or double the true frequency (one octave off). This error is more frequent for tones with strong upper harmonics, at low SNR, and near the extremes of the detection range. A result that is exactly one octave off from the expected pitch is a YIN octave error, not a reflection of the actual pitch. The Troubleshooting page documents when octave errors occur and what to do about them.
OS audio processing affects results. Windows and macOS apply automatic gain control (AGC) and noise suppression to microphone input by default. These processes alter the waveform in ways that affect the sharpness of the YIN difference function minimum, introducing additional measurement uncertainty. Disabling these settings during critical pitch measurement improves accuracy.
The tool detects instantaneous F0, not averaged pitch. The displayed value reflects the fundamental frequency at the moment of each analysis frame — not an average over time. For tones with vibrato, the reading will fluctuate with the vibrato rate. For inconsistent or drifting pitch, the display will track those changes rather than providing a stable centre pitch.
The tool is monophonic. Playing two or more simultaneous notes produces an unreliable detection result. The tool is designed for single-note pitch analysis only.
No Professional Advice
Nothing on OnlinePitchDetector.com constitutes professional music instruction, professional audio engineering services, professional intonation coaching, clinical audiology, or any other form of regulated or certified professional service.
In particular:
- Pitch detection results from this tool should not be used as the sole basis for professional decisions — including instrument setup, vocal health assessment, or intonation documentation for professional recording — without independent professional verification
- Results do not constitute certified pitch measurement for any legal, contractual, or broadcast compliance purpose
- The ±2–5 cents accuracy of this tool is sufficient for most musical practice but may not meet the requirements of applications that demand certified sub-cent precision
No Warranties
OnlinePitchDetector.com and all content and tools on this site are provided “as is” and “as available” without warranties of any kind, either express or implied.
Vincent Sullivan does not warrant that:
- The pitch detector will produce accurate results on every hardware, browser, and OS configuration
- The site will be available without interruption or error at all times
- The technical information on this site is free from inaccuracies or omissions
- The site is free from security vulnerabilities
Limitation of Liability
To the fullest extent permitted by applicable law, Vincent Sullivan and OnlinePitchDetector.com shall not be liable for any direct, indirect, incidental, consequential, or special damages arising from:
- Reliance on a pitch detection result for any professional, commercial, or personal decision
- Intonation, instrument setup, or performance decisions made on the basis of tool results or content from this site
- Any loss — professional, financial, creative, or otherwise — resulting from actions taken based on information published on this site
- Octave errors, noise floor errors, or OS processing artefacts in pitch detection results
- Failure of the tool to produce a result on a specific hardware or browser configuration
The maximum liability of Vincent Sullivan to any user of this site, for any reason, shall not exceed the amount paid by that user to access the site. As OnlinePitchDetector.com is a free service, this amount is zero.
External Links
OnlinePitchDetector.com contains links to external websites including signal processing research, music theory resources, and browser documentation. These links are provided for reference only. Vincent Sullivan does not endorse, control, or accept responsibility for the content, accuracy, or availability of any external site. Visiting an external site from a link on this site is entirely at your own risk.
Changes to This Disclaimer
This Disclaimer may be updated from time to time to reflect changes in the site’s tools, content, or applicable law. The current version is always published at this URL with the “Last updated” date shown above. Continued use of OnlinePitchDetector.com after an update constitutes acceptance of the revised Disclaimer.
Related Pages
- How It Works — full technical documentation of the YIN detection pipeline and accuracy figures
- Troubleshooting — guidance on octave errors, unstable readings, and consistent pitch offsets
- Privacy Policy — how this site handles your data
- Contact — to report content errors or ask technical questions
This Disclaimer applies to all pages and tools on OnlinePitchDetector.com. Written by Vincent Sullivan. Last updated: June 2026.