Written by Daniel Murphy | Last updated: June 2026
About the Tool
What does GuitarChordIdentifier.com do? The tool identifies guitar chords through two modes. In fret input mode, you select your finger positions on a virtual fretboard, and the tool extracts the pitch class set, analyses the intervals, and looks up the matching chord name including inversion. In microphone mode, you play a chord on your guitar, the tool captures audio via the Web Audio API and performs polyphonic pitch detection to extract simultaneously sounding fundamental frequencies, maps them to pitch classes, and identifies the matching chord. Both modes display the chord name, the notes detected, and the inversion where applicable. For the full technical documentation of both pipelines, see the How It Works page.
Which mode is more accurate — fret input or microphone? Fret input is significantly more accurate for most situations. Because you are directly specifying the notes being played, the tool has exact pitch class information with no ambiguity from harmonics or background noise. Microphone mode introduces real accuracy limitations from polyphonic detection — particularly for complex voicings, heavily distorted tone, or ambient noise environments. Use fret input when you want a reliable identification; use microphone mode for quick real-time identification when accuracy is less critical or as a starting point to verify with fret input.
What tunings does the fret input mode support? The fret input mode is calibrated for standard tuning (EADGBe). If you are using an alternate tuning — drop D, open G, DADGAD, or others — the fret positions will produce different pitch classes than the tool expects, and the identification will be incorrect. Alternate tuning support is a documented limitation of the current fret input implementation.
Does the microphone mode require a specific microphone? The tool works with any microphone your browser can access — built-in laptop microphone, USB interface, or condenser microphone through an audio interface. Better microphone quality and frequency response generally produce more reliable polyphonic detection results. The tool is least reliable with built-in laptop microphones for complex chord voicings because their limited frequency response and high noise floor reduce the clarity of individual string fundamentals in the captured spectrum.
Understanding Your Results
What does “G/B” mean in a chord result? The slash notation indicates an inversion — the chord before the slash (G) is the chord name, and the note after the slash (B) is the bass note — the lowest note in the voicing. G/B means G major chord with B in the bass, which is the first inversion of G major (the third of the chord in the lowest voice). Slash chords are common in guitar music because many standard shapes naturally place a non-root note on the lowest played string.
The tool identified my chord as “Cmaj7” but I was playing what I thought was a C chord. Why? If you were playing a standard open C shape (x32010), the notes are C, E, G, C, E — a C major chord. If the result shows Cmaj7, check whether you accidentally included the open high B string (string 1) in your fret input — this would add B to the chord and produce C, E, G, B = Cmaj7. A single extra or missing string selection can change the chord name significantly, particularly when the added note is a seventh or an extension.
The microphone mode identified a completely wrong chord. What happened? The most common causes of completely wrong microphone identifications are: background noise strong enough to generate false spectral peaks, a guitar string buzzing against a fret and introducing additional frequencies, a chord with strong upper harmonics that the harmonic series filter did not fully resolve, or highly distorted tone where harmonic saturation creates a dense spectrum that the detection pipeline cannot reliably parse. For the specific steps to improve microphone results, see the Troubleshooting page.
Why does the tool sometimes show multiple possible chord names? Some pitch class sets match more than one valid chord name depending on which note is treated as the root. The set {C, E, G, B} can be named Cmaj7 (C as root, major seventh chord) or Em/C (E minor with C in the bass, first inversion). The tool displays the most common interpretation first and notes the alternative because neither name is “wrong” — the correct name depends on the harmonic context of the surrounding music.
My chord has an open string I am not pressing — should I include it? Only include open strings that are actually ringing. If a string is muted by your palm or a fretting finger and is not producing sound, do not include it. If it is ringing freely as an open string, include it — the open string’s pitch significantly affects chord identity and inversion. For example, in a standard open D shape (xx0232), the open D string (string 4) is essential to the identification.
Guitar Theory Questions
What is a chord inversion? An inversion occurs when a note other than the chord root is the lowest-pitched note in the voicing. In root position, the root is in the bass. In first inversion, the third is in the bass. In second inversion, the fifth is in the bass. For seventh chords, there is also a third inversion where the seventh is in the bass. Inversions change the sound and function of a chord without changing its identity — a G/B chord contains the same notes as G major, just with B at the bottom instead of G.
What is a pitch class? A pitch class is a set of all notes with the same name regardless of octave. The note G played on any string at any fret is always pitch class G, regardless of whether it is G2, G3, or G4. When the tool identifies a chord, it reduces all detected notes to their pitch classes (removing octave information) and matches the resulting set against chord definitions. This is why the same chord shape played at different positions on the neck produces the same chord name — the pitch classes are the same even though the specific octaves differ.
Why can the same chord have multiple valid names? Music theory allows multiple valid names for the same set of notes when the harmonic context is ambiguous or when different theoretical frameworks apply different conventions. Am7 and Cmaj6 contain the same four notes (A, C, E, G) and are functionally different only by context and bass note. Similarly, Bdim and G7 (no root) share notes and are enharmonically related. The tool identifies the most common interpretation but flags alternatives where they exist.
What is the difference between a power chord and a fifth chord? A power chord (also written as “5 chord” — G5, A5, etc.) contains only the root and the perfect fifth, with no third. Because there is no third, it has no major or minor quality — it is neither major nor minor. Power chords are common in rock and metal because the absence of the third makes them sound powerful and unambiguous through distortion. The tool identifies them as [root]5 (e.g. G5, E5) and notes that no third is present.
Accuracy and Limitations
How accurate is the fret input identification? For standard guitar voicings — common open chord shapes, barre chords, and standard jazz voicings — fret input identification is effectively 100% accurate for the notes you select. The only source of error is selecting the wrong fret or string positions. The tool’s chord database covers standard triads, seventh chords, extended chords (9th, 11th, 13th), suspended chords, and common guitar-specific voicings. Very unusual or highly extended chords not in the database may not be identified.
How accurate is the microphone identification? For simple triads played with clean tone in a quiet environment, accuracy is approximately 80–90%. For seventh chords and more complex voicings, accuracy drops to approximately 60–75% depending on voicing density and microphone quality. Heavily distorted tone, ambient noise, and barre chords on lower-quality microphones significantly reduce accuracy. The microphone mode is most useful as a quick reference for clean-tone playing, not as a replacement for fret input for critical identification.
Does the tool work with a capo? In fret input mode, a capo effectively changes the open string tuning. If you have a capo on fret 2, for example, the open strings are now F#, B, E, A, C#, F# rather than E, A, D, G, B, E. The tool does not currently adjust automatically for capo position — you would need to enter the fret positions relative to the capo and mentally offset the identification by the capo fret. Capo support is a documented feature gap in the current fret input implementation.
About This Website
Who runs GuitarChordIdentifier.com? GuitarChordIdentifier.com is built and maintained by Daniel Murphy, guitar theory educator and audio analysis developer. Daniel writes all content on the site personally. There are no guest contributors, no sponsored content, and no advertisers. For Daniel’s full background and the reasons this site was built, see the Author page.
Is this site free to use? Yes. Both chord identification modes and all educational content on GuitarChordIdentifier.com are completely free. No registration, no account, and no payment of any kind is required.
How do I report an error or ask a technical question? Email contact@guitarchordidentifier.com with the subject line “Content Correction” for factual errors or “Technical Question” for tool questions. Daniel reviews all submissions personally. Response time: 48–72 hours.
Written by Daniel Murphy, founder of GuitarChordIdentifier.com. Last updated: June 2026.