What you need, and what will not work
Klaviero plays on your computer keyboard or by touch, in the browser. A real MIDI keyboard needs Chrome, Edge, Firefox or Opera on a desktop or laptop. Safari and every browser on iPhone and iPad cannot read one. If an iPad is your only device, you play on the screen. The reason is below, in full.
The short version
Why Safari and iOS cannot work
Klaviero reads your keyboard through the Web MIDI API. Apple has not implemented it in Safari and has said publicly that it does not intend to. WebKit lists Web MIDI among the features it decided not to build, alongside Web Bluetooth and Web USB, over fingerprinting and security concerns.
Switching browsers on an iPhone or iPad does not help. Apple requires every browser on iOS to use Safari's engine, so Chrome on iOS is Safari in a different coat. Fifteen months after the EU's Digital Markets Act came into force, no browser vendor had shipped its own engine on iOS.
So this is not a bug we are working on. There is no version of Klaviero that runs on an iPad. If that is your only device, do not subscribe.
The Chrome permission prompt
The first time you open Klaviero in Chrome, you will get a permission dialog asking to use your MIDI devices. That is Chrome, not us. Since Chrome 124 in April 2024 the whole Web MIDI API sits behind that prompt, not just SysEx. Say yes and it will not ask again.
If you accidentally blocked it: click the icon at the left of the address bar, find MIDI devices, set it to Allow, then reload.
What counts as a MIDI keyboard
Any digital piano, stage piano, synth or controller keyboard with a USB port or MIDI out. 25 keys works. 88 works better. Weighted keys are nicer to play and change nothing technically.
If a piece needs a wider range than your keyboard has, Klaviero tells you before you start and offers to fold the out-of-range notes into your range.
Acoustic pianos
There is a microphone mode for playing along with an acoustic piano. It is not scored, because microphone pitch detection is not accurate enough to judge a ten-note chord honestly. If you want a score, you need MIDI.
Bluetooth MIDI
It works where your operating system supports it. It also adds latency, and in a game judged per note, latency is the whole product. Use a cable.
Frequently asked
Does Klaviero work on iPad?
No. No browser on iPad supports Web MIDI, and Apple requires them all to use Safari's engine.
Does Klaviero work in Safari on a Mac?
The computer keyboard works. A MIDI keyboard does not: use Chrome, Edge, Firefox or Opera, or the macOS desktop app.
Do I need a MIDI keyboard?
No, not to start. Your computer keyboard reaches 17 keys and the app plays the notes out of reach. For every key and both hands, use a MIDI keyboard. There is also a microphone mode for acoustic pianos.
Is there an Android version?
Chrome on Android supports Web MIDI, so it runs. It has not been tested as a primary platform and the screen size is against you.
Why does Chrome ask permission to use my MIDI devices?
Since Chrome 124 in April 2024 the whole Web MIDI API sits behind a permission prompt. That dialog is Chrome's, not Klaviero's. Allow it once and it will not ask again.