How product claims are checked
Testing Methodology
We separate deterministic software checks from real-device listening tests. A passing calculation test does not prove that every microphone, room, browser, or instrument will produce the same result.
Last updated: July 26, 2026
Reference pitch and note calculations
Target frequencies use 12-tone equal temperament with A4 set to 440 Hz by default. The implementation converts MIDI note values to frequency and measures the ratio between detected and target frequencies in cents.
Automated checks verify representative target frequencies and preserve a full 1,200-cent difference between notes one octave apart. They also check that displayed tuning definitions and explanatory copy stay aligned with the application data.
What the automated checks cover
- Reference-frequency calculations and cents deviation.
- Octave-sensitive note definitions for supported instrument tunings.
- Consistency between the tuning catalog and localized tuning copy.
- Route availability and links between related guides and tools.
- Production compilation, static generation, canonical URLs, and sitemap policy.
Browser and microphone behavior
The browser requests microphone access and processes the live signal locally through the Web Audio API and the pitch-detection engine. Input hardware, automatic gain control, room noise, harmonics, attack transients, and browser processing can all affect the detected pitch.
A practical check uses one isolated string or stable reference tone at a time, waits for the reading to settle, and compares the displayed note, frequency, and cents deviation with the expected target. Device and browser details must be recorded before an article receives a “Last tested” date.
Article-level evidence
A source link means the cited reference was used to check a core claim. A “Last tested” date has a narrower meaning: someone followed a recorded procedure using the relevant product or instrument. We do not infer hands-on testing from research alone.
Known limits
- The tuner is not represented as a laboratory-certified measurement device.
- String-gauge suggestions are starting points, not universal prescriptions.
- Instrument setup outcomes vary with scale length, construction, hardware, action, and playing style.
- Work that requires nut filing, truss-rod adjustment, or structural diagnosis may need a qualified technician.
For a plain-language explanation, see how the tuner works. To report a reproducible problem, use the contact page and include the device, operating system, browser version, instrument, target tuning, and the note that failed.