Comparison

Hex MIDI vs Harmonaut

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Hex MIDI

Features
Read full description

Hex MIDI is an isomorphic MIDI controller and microtonal synthesizer. Instead of the standard piano keyboard, notes are arranged in geometric hexagonal grids - meaning chord shapes, scales, and intervals remain identical across every key. Whether you want to play alternative keyboards like the Wicki-Hayden or Jankó, compose in 19-EDO / 31-EDO microtonal tunings, or control your DAW over MIDI and MPE, Hex MIDI gives you the tools to explore harmony through geometry. Built-In Keyboard Layouts: • Wicki-Hayden – Classic concertina layout with fifths/fourths diagonals and octave columns. • Jankó (Classic & Vertical) – Whole-tone rows with uniform chord fingerings. • Harmonic Table – Euler's Tonnetz grid: major/minor third diagonals with vertical fifths for visual chord building. • Bosanquet-Wilson (Maupin) – Generalized flat-top hex layout built for microtonal navigation. • Harpejji – Whole-tone string layout with semitone vertical progression. • Chromatic Button Accordion – Authentic C-System and B-System (Bayan) layouts. • Fourths & Fifths – String instrument tunings for guitarists, bassists, and violinists. • Major Thirds & Diminished Harmonica – Symmetrical grid layouts. • Custom Layout Editor – Build and save your own hexagonal or rectangular grids. Microtonal & Tuning Engine: • EDO Presets: 19-EDO, 22-EDO (Shruti), 24-EDO (Quarter-tone / Maqam), 31-EDO (Meantone), 41-EDO, 53-EDO, and sub-12 tunings (5-EDO Slendro, 7-EDO, 10-EDO). • Scale Formats: Bohlen-Pierce (13-EDT), Just Intonation, and custom scale generation. • Scala Support: Import standard .scl tuning files and .kbm keyboard mappings. • Visual Color Modes: 5ths spiral color coding, Tonnetz harmonic spectrum, and minimal two-tone palettes. • Note Labels: Display note names with arrow accidentals, Solfège, interval numbers, or exact Hz. MIDI & Expressive Performance: • MIDI I/O: Connect via USB MIDI to hardware synthesizers, external keyboards, and DAWs (Ableton, Logic, Reaper, Bitwig). • MPE & Vibrato: Per-note microtonal pitch-bend routing and touch vibrato. • MTS Support: Real-time MIDI Tuning Standard SysEx transmission for compatible synths. • Touch Control Pads: Integrated dual X/Y pads for assignable pitch, modulation, and CC filters. • Built-In Sound Engine: High-fidelity soundfont player with instant response.

About

Harmonaut

Create music by feel without needing music theory. This app generates rich chords and smooth progressions, allowing you to shape the mood with intuitive controls. Save and reorder your musical ideas effortlessly.

Highlights
  • Play by feel, no theory required
  • Shape mood with tension and brightness faders
  • Smooth voice leading for flowing progressions
  • Chords named for musicians
  • Save and reorder progressions
  • Works on iPhone and iPad
Features
Read full description

Harmonaut™ is a chord instrument you play by feel. Press a key and hear a rich chord, voice-led smoothly from the last one, no theory needed. Build a progression, shape its mood, and export it as MIDI for your track. Two faders let you shape the mood as you play: more tension or less, brighter or darker, even major to minor. Chase a moody electronic progression, a warm lo-fi loop, a jazzy turn, a cinematic swell, or a simple pop hook. It all comes from your intent, not from naming chords. HOW IT PLAYS • Tension that actually resolves: chords that lean, pull home, and land, so your progression goes somewhere instead of just floating • Every one of the twelve keys is in play: reach past the obvious chords for richer, more surprising color, and it still sounds right • Build a whole progression, not just four chords: every chord you play lands in your trail, ready to reorder or duplicate to try new versions in seconds • Pick up right where you left off: your ideas are saved for you TAKE IT TO YOUR TRACK • Export any progression as a MIDI file and drop it into BandLab, GarageBand, or any DAW that opens MIDI, then play it through any instrument you like • Export to iReal Pro format to keep a chord chart or practice over the changes • Harmonaut Pro unlocks MIDI export, iReal Pro export, and unlimited saved progressions IT SOUNDS GOOD FOR A REASON Every chord is voice-led from the one before it, live, as you play: the notes move the shortest way, so a progression flows instead of jumping around. That's the finished feeling you hear in the songs you love. Push Intensity and the voicings open up: lush 9ths, bright 13ths, and altered dominants like G7#9b13, the colors session keyboard players reach for. And Harmonaut names every chord the way musicians actually write it, like Ebmaj7, so you can hand your progression to a session player, a bandmate, or a producer and they'll play it back exactly, first time. No box to buy, nothing to charge, no menus to dig through. It's already in your pocket. Whether it's your first progression or a sound you can hear but can't name, Harmonaut meets you where you are. See the end user license agreement at the following link: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

Hex MIDI4 screens
Harmonaut4 screens

Verdict

The call

The clearest difference is in-app purchases: Harmonaut at none against Hex MIDI's 1. Harmonaut also leads on update cadence (every 10 days vs monthly). On price, ads, device support and iOS requirement there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Hex MIDI sells 1 one-off in-app purchase. Harmonaut asks for nothing beyond the download.

UpkeepUpdate frequency

Hex MIDI ships an update monthly, Harmonaut every 10 days. The most recent releases landed on October 4, 2026 and October 8, 2026 respectively.

Scorecard2 real differences · 8 level
Hex MIDI versus Harmonaut: the parameters behind the verdict, then further details
ParameterHex MIDIHarmonaut
PriceFreeFree
Rating—5.0 (6 ratings) — better
Positive reviews—100.0% of reviews
Number of ratings—6 — better
Update frequencyMonthlyEvery 10 days — better
AdsNoNo
In-app purchasesYesNo — better
Monetization—Free with in-app purchases
DevicesiPhone, iPadiPhone, iPad
Requires iOS17.017.0
Further details — not scored
Size95 MB117 MB
Age rating4+4+
DeveloperTrung Dung HoangDistrict One Mobile, LLC

In-app purchases

1 purchases

Hex MIDI

One-time1
  • Hex MIDI Pro$12.99
None

Harmonaut

No in-app purchases

Questions

Is Hex MIDI free?
Hex MIDI is free to download, with in-app purchases available.
Is Harmonaut free?
Harmonaut is free to download, with no in-app purchases.
Do Hex MIDI or Harmonaut have ads?
Neither Hex MIDI nor Harmonaut shows ads.
Which is updated more often, Hex MIDI or Harmonaut?
Hex MIDI ships an update monthly, and Harmonaut every 10 days. Most recently, Hex MIDI was updated on October 4, 2026 and Harmonaut on October 8, 2026.

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