Free Online Chromatic Tuner

Tune any instrument to perfect pitch with this free online chromatic tuner. Classic needle-gauge display, 15+ instrument presets (guitar, bass, ukulele, violin, cello, banjo, mandolin and more), strobe mode, adjustable A4 reference (standard A440 or any value from 415 to 450 Hz), and reference pitch playback. 100% browser-based — no downloads, no data uploaded.

All 12 notes of the chromatic scale are detected in equal temperament, with deviations displayed in cents (hundredths of a semitone). This makes it equally useful as a guitar tuner for standard and alternate tunings, a bass tuner, a violin fine-tuner, a wind instrument check, or a quick intonation reference for any pitched instrument. Unlike a dedicated clip-on instrument tuner, this strobe tuner and needle tuner run entirely in the browser with no hardware required. If you need to verify the exact frequency of a reference note, pair this tool with the A4 tuning frequency tool or use the interval calculator to work out the precise pitch relationship between two notes.

🔒 100% private — all pitch detection runs locally in your browser. No audio is ever uploaded or stored.

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Space Start/Stop F Freeze R Ref Tone C Calibrate T Strobe ↑↓ A4 Adjust

Microphone:

Sensitivity -45 dB

Instrument:

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— Hz

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WAITING

A4 Reference: 440.0 Hz

FROZEN

Analyze Audio File

📁 Drop audio file here or click to browse MP3, WAV, OGG, FLAC — max 50 MB

Session Stats

Readings

In Tune

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Best Cents

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Duration

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History Log

Time	Note	Hz	Cents	String

How to Use the Chromatic Tuner

Select Your Instrument

Choose from 15+ presets — Guitar (Standard, Drop D, Open G, DADGAD), Bass, Ukulele, Violin, Viola, Cello, Banjo, Mandolin, 12-String, or Chromatic mode for any note. The string buttons update to show target notes for your tuning.
Start the Tuner

Click "Start Tuner" and grant microphone permission. Select your preferred input device if you have multiple microphones. All processing happens 100% locally in your browser — no audio is uploaded.
Play a String

Pluck or bow a single string. The tuner automatically detects the pitch and shows the nearest note on the gauge. If you selected an instrument preset, the nearest target string is highlighted. Click a string button to lock to a specific string.
Read the Needle Gauge

The needle swings left for flat and right for sharp. Center (0 cents) means perfectly in tune. The display glows green when you are within ±5 cents. Tune your instrument until the needle is centered and the badge shows "IN TUNE".
Use Reference Tones & Strobe Mode

Click "Play Reference Tone" to hear the target pitch through your speakers. Toggle Strobe Mode for an alternative visualization where horizontal bars stop scrolling when in tune — preferred by many professional tuners.

Equal Temperament vs Just Intonation: Why Is a Tuner in Cents?

Modern tuners — including this one — measure pitch in equal temperament (ET), which divides the octave into 12 perfectly equal semitones using the frequency ratio 2^1/12 ≈ 1.0595. Every semitone step is identical, so every key on a piano sounds equally usable. The trade-off is that ET intervals are slightly impure: a major third is about 14 cents sharper than the acoustically pure 5:4 ratio, and a perfect fifth is about 2 cents flatter than the pure 3:2 ratio. These small errors spread the mistuning evenly across all keys. You can verify the exact Hz difference between any two notes with the interval calculator.

Just intonation (JI) instead uses small whole-number frequency ratios — 3:2 for a perfect fifth, 5:4 for a major third — that produce beatless, pure intervals. The problem is that these pure ratios only work cleanly in one key; modulating to another key requires retuning. This is why fixed-pitch instruments like pianos use ET rather than JI. String quartets and choirs can nudge individual notes toward pure JI intervals in a single key, and a chromatic tuner will show those nudges as small cents deviations from the ET target — that is not wrong, it is an intentional expressive choice. To explore how a reference pitch shift affects all interval relationships, try the A4 tuning frequency tool.

Frequently Asked Questions

What instruments can this chromatic tuner tune?

This tuner works with any pitched instrument. Built-in presets include Guitar (Standard, Drop D, Open G, DADGAD), Bass (4- and 5-string), Ukulele (Soprano and Tenor), Violin, Viola, Cello, Banjo, Mandolin, and 12-String Guitar. Select "Chromatic" mode to tune any note without preset strings.

How accurate is the chromatic tuner?

The YIN pitch detection algorithm achieves ±1–2 cents accuracy for clear, sustained tones. For best results, tune in a quiet environment with your instrument close to the microphone. Use the Calibrate button to filter background noise.

What is the difference between chromatic and instrument mode?

Chromatic mode detects any note and shows cents deviation from the nearest semitone. Instrument mode (e.g., Guitar Standard) shows string buttons and auto-detects which string you are playing, displaying cents deviation from that specific target pitch. Use instrument mode for faster tuning of specific strings.

What is strobe mode and when should I use it?

Strobe mode displays scrolling horizontal bars that move at a speed proportional to the pitch error. When the bars stop moving, you are in tune. Strobe tuners are favored by professional technicians because they make very small pitch deviations easier to see than a needle gauge. Toggle strobe mode with the button or press T.

Why would I change the A4 reference from 440 Hz?

Standard concert pitch is A4 = 440 Hz, but some orchestras tune to 442 Hz (common in Europe) or 443 Hz. Baroque ensembles often use 415 Hz. Some musicians prefer 432 Hz (alternative tuning). The A4 slider lets you match any ensemble's reference pitch. All note calculations update instantly.

Can I tune using an audio file instead of a microphone?

Yes! Drag an audio file (MP3, WAV, OGG, FLAC) into the upload zone or click to browse. The tuner analyzes the file offline using an OfflineAudioContext and shows the detected pitch. This is useful for checking recordings or tuning reference files.

Is my audio data private?

Your audio is 100% private. All pitch detection happens entirely in your browser using the Web Audio API. No audio is recorded, stored, or transmitted. The tool works completely offline once loaded.

What is a cent, and how many cents off is acceptable?

A cent is one hundredth of a semitone — the smallest unit of pitch deviation shown on a tuner needle. There are 100 cents between any two adjacent notes. For most instruments, being within ±5 cents is considered acceptably in tune to an average listener; professional musicians and studio engineers typically aim for ±2 cents. Beating (the wavering sound between two mismatched pitches) becomes audible around 5–10 cents, so smaller deviations matter most in ensemble playing.

How do I tune alternate guitar tunings like Drop D or DADGAD?

Select the matching preset from the Instrument drop-down — Guitar (Drop D) or Guitar (DADGAD) — and the string buttons automatically update to display the correct target notes for that tuning. Pluck each string in turn; the tuner auto-detects the nearest target string and shows the deviation in cents. If you use a non-standard alternate tuning not in the preset list, switch to Chromatic mode and tune each string to the specific note name you need.

Can I use this chromatic tuner on a phone or tablet without a clip-on tuner?

Yes. The tuner works on any modern mobile browser (Chrome, Safari, Firefox for Android) that supports the Web Audio API and microphone access. Hold your phone close to the strings and tune in a quiet environment for best results — the built-in phone mic is sufficient for acoustic instruments. For electric guitars plugged into an amp, position the phone near the speaker cabinet. No clip-on hardware tuner, app download, or account is required.

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