Is temperat.io really free?

Yes — 100% free, no ads, no account required. All audio processing happens locally in your browser.

Do I need to download anything?

No. temperat.io runs entirely in your browser. You can optionally install it as a PWA for offline access.

Does temperat.io work on my phone?

Yes. It works on any device with a modern browser and a microphone. The interface is fully responsive.

Why can't I hear anything / the mic isn't working?

temperat.io needs microphone access to detect pitch. Click the lock icon in your address bar → Site Settings → Microphone → Allow, then reload the page.

How do I connect a MIDI keyboard?

Plug your USB MIDI keyboard into your computer, then switch to MIDI mode using the toggle in the footer. Web MIDI works in Chrome, Edge, Opera, and Brave — not Safari or Firefox.

What does A4 = 440 Hz mean?

A4 is the note A above middle C. The standard tuning reference is 440 Hz. Some orchestras tune to 442 Hz, and some historical tunings use 432 Hz. You can adjust this in the tuner settings.

← Back to app

Help & FAQ

Everything you need to get the most out of temperat.io.

Quick Start

Open temperat.io

Works on any device with a browser — phone, tablet, or desktop.

Allow microphone

Or connect a USB MIDI keyboard for zero-latency polyphonic input.

Start playing

Notes, chords, tuning, and key signatures are detected in real time.

Tools

🎵

Play

The home screen. Notes scroll across a grand staff as you play. Single notes show as letter names; simultaneous notes show chord symbols (Cm7, Gsus4, etc). Supports both microphone and MIDI input. Use the virtual keyboard to tap notes manually.

🎯

Tuner

High-precision strobe tuner. Play any note and see exactly how many cents sharp or flat you are. Supports adjustable A4 reference (432–446 Hz), stretch tuning for acoustic pianos, and noise suppression. Color-coded: green = in tune, yellow = close, red = off.

🎹

Practice

Interactive exercises: random note identification, scale walking (major, minor, modes), and chord building (triads, 7ths). Tap any target note to hear what it should sound like. Real-time scoring tracks your accuracy.

🥁

Metronome

Set tempo with a slider, use Tap Tempo to match a beat, or pick from BPM presets. Supports 6 time signatures (4/4, 3/4, 6/8, 2/4, 5/4, 7/8). Runs independently alongside other modes.

Frequently Asked Questions

General

Audio & Microphone

MIDI Keyboard

Browser Compatibility

Browser	Mic	MIDI	PWA	Notes
Chrome (desktop)	✓ Full	✓ Full	✓ Full	Best experience — all features supported.
Chrome (Android)	✓ Full	✓ Full	✓ Full	Full support including USB OTG MIDI.
Edge	✓ Full	✓ Full	✓ Full	Same engine as Chrome — full support.
Safari (macOS)	✓ Full	✗ None	~ Partial	Mic works great. No Web MIDI support. PWA installs but no install prompt.
Safari (iOS)	✓ Full	✗ None	~ Partial	Mic works. No MIDI. Use "Add to Home Screen" to install.
Firefox	✓ Full	✗ None	✗ None	Mic works. No Web MIDI. No PWA install support.
Opera / Brave	✓ Full	✓ Full	✓ Full	Chromium-based — full support.

temperat.io requires a browser with Web Audio API support and HTTPS. All modern browsers meet these requirements.

Troubleshooting

Microphone not detected

Make sure your device has a microphone (or plug in an external one).
Check that no other app or tab is using the mic exclusively.
Click the lock icon (🔒) in your browser's address bar → Site Settings → Microphone → Allow.
On iOS: Settings → Safari → Microphone → Allow.
Reload the page after granting permission.

Audio is choppy or laggy

Close other audio-heavy tabs or apps (video calls, music streaming).
Try Chrome or Edge — they typically have the lowest Web Audio latency.
On mobile, make sure your device isn't in battery saver mode (this throttles audio processing).
If using Bluetooth headphones, switch to wired — Bluetooth adds ~150ms latency.

MIDI keyboard not recognized

Confirm you're using Chrome, Edge, or another Chromium browser (Safari and Firefox don't support Web MIDI).
Plug in the MIDI keyboard before opening temperat.io, or refresh after connecting.
Try a different USB port or cable.
On macOS: open Audio MIDI Setup and verify the device appears there.
On Windows: check Device Manager → Sound, video and game controllers.

Page won't load or shows a blank screen

Enable JavaScript — temperat.io requires it for audio processing.
Clear your browser cache (the service worker may be stale).
Try an incognito/private window to rule out extensions.
Make sure you're on HTTPS — microphone access requires a secure connection.

Keyboard Shortcuts

Key	Play	Tuner	Practice
`Space`	Insert a rest	Start / stop listening	Start / stop listening
`Backspace`	Undo last note	—	—
`Escape`	Stop listening	Stop listening	Stop listening
`?`	Toggle help	Toggle help	Toggle help

Music Terms Glossary

Cents (¢): A unit measuring pitch deviation. 100 cents = one semitone. When tuning, aim for ±5¢ or less.
A4 Reference: The frequency that defines the pitch of all other notes. Standard concert pitch is A4 = 440 Hz.
Interval: The distance between two notes. For example, C to E is a major third (4 semitones).
Scale: An ordered set of notes. C major = C D E F G A B. Modes are rotations of scales (Dorian, Mixolydian, etc).
Chord: Three or more notes played simultaneously. A C major triad = C E G.
Semitone: The smallest interval in Western music — the distance from one key to the very next key on a piano (including black keys).
Inharmonicity: Piano strings don't vibrate perfectly — their overtones are slightly sharper than pure math predicts. This is why acoustic pianos need stretch tuning.
Polyphony: Playing multiple notes at the same time. MIDI keyboards send each note individually, making polyphonic detection very accurate. Microphone-based detection uses ML to separate overlapping pitches.

Contact & Feedback

Found a bug? Have a feature request? We'd love to hear from you.

hello@temperat.io

Or open an issue on GitHub