What Is a Full Size MIDI Keyboard?
Updated Nov 12, 2026 · By 
Jonah Mercer · Editorial policy
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A full size MIDI keyboard is a controller with 88 keys, the same count as a piano, and keys the same size as piano keys. It sends MIDI notes to a computer or sound module instead of making sound on its own. Smaller controllers use fewer keys or smaller mini keys, so they take up less desk space.
88 keys, the same as a piano
Full size means the full piano range: 88 keys from the lowest note to the highest. A controller with fewer keys covers part of that range, and octave buttons shift the keys you have to reach higher or lower notes. Count the keys first when you compare controllers, since the count decides how much of the range sits under your hands.
Full-size keys, not mini keys
Full-size keys are the same size as piano keys, so your fingers land where they expect to. Mini keys are narrower and closer together, which suits a small desk or travel but leaves less room for each finger. The key size is the first thing to check, since the two play differently.
What a MIDI keyboard does
A MIDI keyboard sends note and control messages to software or hardware that makes the sound. It sends its notes to a computer, a sound module or an app, and that device makes the sound you hear. The USB cable carries both the MIDI messages and the power.
Pads, knobs and wheels
Many controllers add pads for drums, knobs for volume and other settings, and pitch and modulation wheels beside the keys. Pads trigger sounds with a tap, knobs turn settings without reaching for the mouse, and the wheels bend the pitch or add vibrato while you play. Look at what each controller adds beyond the keys, since the extras decide how much you can do from the keyboard itself.
Connect it with one USB cable
Plug the USB cable into the controller and the computer, and the computer sees it as a MIDI device. Most controllers need no separate power supply, since the USB cable powers them. Open your recording software, pick the controller as the MIDI input, and the keys play the software instrument you loaded.
What you need
M-AUDIO Keystation 49 MK3 USB MIDI Controller
A 49-key controller with full-size velocity-sensitive keys, pitch and modulation wheels, a volume fader, a sustain pedal input, and Ableton Live Lite included, with a 1-year warranty.
- Keys: 49
- Software named in listing: Ableton Live Lite
- USB-MIDI
- 1-year warranty stated
Akai Professional MPK Mini IV 25-Key USB-C
A 25-key controller with velocity-sensitive mini keys, 8 MPC pads, 8 knobs, a full-color screen, and Ableton Live Lite included, with a 1-year warranty.
- Keys: 25
- Pads: 8
- Knobs / faders: 8
- Software named in listing: Ableton Live Lite
- USB-MIDI
- 1-year warranty stated
- 2.2 lb, the lightest here
Novation Launchkey 49 MK4 USB MIDI Keyboard
A 49-key controller with semi-weighted keys, 16 pads with polyphonic aftertouch, 9 faders, pitch and modulation wheels, an OLED display, and a 3-year warranty.
- Keys: 49
- Pads: 16
- Knobs / faders: 9
- Aftertouch
- Software named in listing: Ableton Live
- USB-MIDI
- 3-year warranty stated
Akai Professional MPK Mini Plus 37-Key USB
A 37-key controller with velocity-sensitive mini keys, 8 MPC pads, 8 knobs, a 64-step sequencer, and MIDI and CV/Gate outputs, with a 1-year warranty.
- Keys: 37
- Pads: 8
- Knobs / faders: 8
- USB-MIDI
- 1-year warranty stated
These come from our ranked list Best MIDI Keyboard, which compares them spec by spec.
Frequently asked questions
Is a 49-key keyboard full size?
No. A full size keyboard has 88 keys, so a controller with fewer keys covers part of the range. It can still have full-size keys, which is about the size of each key rather than the count.
Do MIDI keyboards make sound on their own?
No. A MIDI keyboard sends messages to software or hardware that makes the sound. Without a computer, a sound module or an app connected, pressing a key makes no sound.
What is the difference between full-size and mini keys?
Full-size keys match piano keys in size, while mini keys are narrower and closer together. Mini keys fit smaller controllers and travel setups, and full-size keys suit players who want the same spacing as a piano.
Can I use a MIDI keyboard with a phone or tablet?
Some controllers work with phones and tablets over USB, and others work only with a computer. Check the controller's connection notes for your device before you buy, since the cable and the app decide whether it works.
Ranked MIDI keyboards lists
More how-to guides
Product details come from each Amazon listing and can change. Check the listing before you buy.