PocketMIDI: MIDI Keyboard

JdevStudio

In-app purchases

About this app

PocketMIDI is a low-latency MIDI synthesizer and piano for Android, built for live performance. The core app is completely free — and everything it did for free before, it still does for free.

Plug in a USB MIDI keyboard or play the on-screen keys: studio-quality sound with a latency target under 40 ms. No ads, no tracking, no subscription, no account.

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FREE — AND STAYING FREE
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No trial, no sign-up:
• Four built-in instruments — Grand Piano (Salamander V3, A0–C8), Strings, Dark Pad, Synthesizer
• USB MIDI keyboards and the multi-touch on-screen keyboard, 96-voice polyphony, velocity and sustain pedal
• Arpeggiator, chord mode, transpose, metronome
• Full synth editor — waveforms, ADSR, filter
• Presets: save, load, export, import
• Recording with piano roll and playback, exported as WAV or M4A audio
• Performance monitor and every setting

No feature that was free has been moved behind a purchase, and none will be.

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OPTIONAL ADD-ONS
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Want a bigger palette? 23 extra instruments are one-time purchases — buy them one at a time, or unlock all of them together. No subscription.

• Keys — Upright Piano, Organ
• Strings — Solo Violin, Violin Section, Viola Section, Cello Ensemble, Solo Contrabass, Harp
• Brass — Trumpet, French Horn, Tenor Trombone
• Woodwinds — Flute, Piccolo, Oboe, Clarinet, Bassoon
• Percussion — Marimba, Xylophone, Glockenspiel, Tubular Bells, Timpani
• Bass — Finger Bass, Pick Bass
• Plus .mid export of your recordings, for editing as notes in a DAW — included with the all-sounds unlock

Preview any add-on before you buy. Packs download on demand so the app stays small, then work offline like any built-in sound, with the same ADSR editor. Purchases are one-time and restore when you reinstall or change device.

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FEATURES IN DETAIL
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USB MIDI — connect any class-compliant keyboard over OTG. Note on/off and sustain (CC64) route straight to the audio engine. Optional auto-launch on connect.

ON-SCREEN KEYBOARD — 2 octaves (C3–C5), up to 10 simultaneous touches, tap position sets velocity.

ARPEGGIATOR — patterns, rates including triplets, octave span, gate, latch. Tap-to-type BPM synced with the metronome. Chord mode fires full chords and arpeggios as you play.

SYNTH EDITOR — sine, saw, square, triangle; ADSR (attack and decay 1 ms–4 s, sustain 0–100%, release 1 ms–8 s); low-pass filter with cutoff and resonance.

PRESETS — name and save instrument and synth settings, recall them instantly mid-performance, export and import as JSON.

RECORDING — real-time piano roll, fixed-timeline playback with a moving playhead, pinch to zoom, drag to seek.

METRONOME — 20–300 BPM; time signatures 2/4, 3/4, 4/4, 6/8, 7/8, 5/4; visual pulse.

PERFORMANCE — live monitor for active voices, buffer size, sample rate, estimated latency and underruns.

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SUPPORT
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Free and paying users get the same support at the same priority. A bug in the free app is fixed with the same urgency as one affecting a purchase — buying doesn't move you up the queue, and not buying doesn't move you down it.

[e-mail]
https://pocketmidi.jdevstudio.app/support.html

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TECHNICAL
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Oboe 1.9.0 (AAudio, OpenSL ES fallback) • ~4 ms buffer @ 192 frames, 48 kHz • automatic stream restart • Android 8.0+. Plays fully offline; the internet is used only to browse, preview and download add-ons.

Salamander Grand Piano V3 samples by Alexander Holm, used under CC BY 3.0 with no modifications: https://creativecommons.org/licenses/by/3.0/

Ratings and reviews

I would love to be able to alter the chords but try as I might, there doesn't seem to be a way. I'm very experienced with these apps & should have little to no problems finding a way of changing what chords can be played. if there is a way to choose your chords, you must need a degree which is far too hard! useless to me, I want to play a D maj but it's stuck DM! nothing can be done to changed individually. every other app has an option to Taylor the chords but this doesn't seem to have it!

Running Key Station Pro 88 with my S23 Ultra. Thank you. Latency is low (no delayed input to sound) and no ads, both of which are great. I was using my old Win 7 PC with Reason and Line 6 UX2 but took ages to crank up, whereas this PocketMIDI app allows me to plug and play immediately. Well recommended!

great app! all the functions are straightforward and easy to understand. would however love if there was an option to upload your own sound banks

What’s new

🎙️ Upgraded Recording & Metronome

Header Record Button: Easily start recording right from the top bar for faster access.

Tempo-Synced Count-In: Get into the groove smoothly with a built-in metronome count-in that stays perfectly synced to your tempo before recording begins.

🎛️ Quick Sound Resets

Reset ADSR & Synth Filters: Instant double-tap or reset controls allow you to restore your sound envelope and filter settings back to their default state anytime.