8 Best FM Synth Apps for iPhone (DX7 Clones and Easy Ones)

KQ Dixie 26 is the best FM synth app for iPhone if you want the full DX7: six operators, 32 algorithms and support for the thousands of DX7 patch files shared online. The best free picks are King of FM, which plays sampled DX7 and SY77 sounds, and M2DX, a free 6-operator engine that loads the same patch files. If operators and algorithms sound like homework, the last two picks on the list have far fewer controls to learn.

One of those two is ours, marked (ours) at number 7. We make it, so weigh that entry accordingly. Every other app was checked against its developer’s own listing, and their prices are US App Store prices in September 2026.

FM synthesis uses one sine wave to wobble the pitch of another at audio speed, which adds harmonics. Each sine wave is called an operator, and an algorithm is the wiring diagram that says which operators modulate which. Yamaha’s DX7 from 1983 had six operators and 32 algorithms. Two apps below copy that design, three trim it to four operators, and the rest sample the old hardware or add FM to a simpler synth.

Best DX7 apps for iPhone (plus a 4-operator one)

1. KQ Dixie 26 (Ryouta Kira). Paid ($8.99), iPhone and iPad, plus Apple silicon Macs. The most complete DX7-style synth on iOS. The developer says nearly all of its 156 voice parameters match the original DX7, so DX7 patch banks load straight from .syx files, zipped banks included. On top of the DX7 design it adds a filter, delay, unison, a multitimbral mode, microtuning from Scala files and an AUv3 version with multiple outputs. The older KQ Dixie Legacy is still listed at $10.99, but the developer marks it deprecated and points buyers to 26, so buy this one.

2. M2DX (Hakaru Hirose). Free with an optional $9.99 Pro upgrade, iPhone (iOS 18 or later). A new 6-operator, 32-algorithm synth whose engine, according to the developer, is a bit-exact port of the open-source Dexed engine. The free version has the full engine, an on-screen keyboard, DX7 .syx import and the AUv3 plug-in. Pro is a one-time purchase that adds layering of up to eight patches per note (named after Yamaha’s TX816 rack), a Mark I engine mode, 12-bit DAC emulation and unison of up to 16 voices. For a free DX7 clone, start here.

3. KQ Tixie (Ryouta Kira). Paid ($8.99), iPhone and iPad. From the KQ Dixie developer, modeled on the 4-operator FM synths of the 1980s. It does not load DX7 patches. It reads SysEx patches from 4-operator Yamaha gear such as the DX100, TX81Z and V50 instead, and each operator can use any of the TX81Z’s eight waveforms, where the DX7 had sine waves only. Four operators are quicker to program than six and still cover basses, bells, electric pianos and leads. It also has MPE, layering of up to eight sounds, and effects inspired by the Yamaha V50 and Korg DS-8.

If you already use Dexed on a computer, there is also a $3.99 iOS port called Dexed Synth (George Rosar), designed with small screens in mind.

Best free FM synth apps for iOS

4. King of FM (AudioKit Pro). Free, no ads or in-app purchases, iPhone, iPad and Apple silicon Macs. A preset player built on more than 10,000 samples of DX7, DX7II, TX81Z and SY77 sounds, with 300+ presets and effects including chorus, phaser, ping-pong delay and reverb. Because it plays recordings, there are no operators to edit, which suits someone who wants a classic DX electric piano in a song tonight and has no interest in programming one. AudioKit calls it the new version of FM Player 2, so if you are looking for FM Player, this is where it went.

5. FM Essential (Yamaha). Free, iPhone and iPad. Yamaha’s own FM app, built on technology from its 4-operator DX100, TX81Z and V50. The free app has 10 preset voices you can edit and play, 20 chord pads, an arpeggiator with 64 patterns and a 16-pad drum part. Connecting a Yamaha MX BK, BU or WH synth brings the total to 271 voices and lets you save your own, so the app makes the most sense for MX owners.

6. AudioKit Synth One (AudioKit Pro). Free and open source, no ads or in-app purchases, iPhone and iPad. A hybrid synth with five oscillators: two analog-style ones, a sub, noise and a dedicated FM oscillator. You mix the FM oscillator in with the others, so you can hear what FM adds to a sound without learning operators first. It has 300+ presets, a 16-step sequencer and an arpeggiator. It runs as a standalone app only, since AUv3 support is still listed as on the roadmap.

Best FM synth for beginners

FM has a reputation for being hard to program. On a 6-operator synth, a small change to one ratio can change the whole sound, and the DX7 shapes each operator with four rates and four levels, which is less familiar than the attack, decay, sustain and release (ADSR) found on most synths. These two apps give you far fewer controls to learn.

7. Gelato Synth (ours) (Gelato Audio). Free with one $4.99 in-app purchase, iPhone. An FM and wavetable synth with one idea per page and fat sliders. The FM page has two controls, Amount and Envelope to FM (a bright attack that settles into a purer tail), and Osc B’s Ratio slider runs from x0.5 to x8. Notes mode only shows the notes of the scale you pick, so nothing sounds wrong while you experiment, and a live oscilloscope shows the wave change as you move each slider. It is a standalone app with no MIDI or AUv3, so producers should look higher up this list. The full feature list is on our synth page.

8. BLEASS Omega (BLEASS). Paid ($14.99), optional preset packs ($2.99 to $3.99, one free), iPhone and iPad. Four-operator FM with 11 algorithms, where all four operators and their envelopes are edited from one screen, so nothing hides behind menu pages. An analog-style waveshaper and a multi-mode filter add drive and resonant sweeps on top of the FM tone, and it has chorus, tremolo, delay and reverb built in, plus MPE and AUv3. It costs the most on this list, and it is the one to buy when you want to program real operators and algorithms, with four operators to learn where the DX7 has six. Desktop versions for Mac and Windows exist too.

To learn what ratio and amount actually do before you spend anything, read FM synthesis explained simply.

FM Essential vs KQ Dixie vs King of FM, compared

FM Essential, KQ Dixie and King of FM are three different kinds of app: a 4-operator Yamaha synth, a full DX7 clone and a sample player. The table puts all eight side by side.

If you want the DX7 itself, with every parameter and the ability to load vintage cartridges, KQ Dixie 26 is the pick, and it is the only one of the three you pay for. King of FM sits at the other end: free and huge, but fixed, since you choose presets and effects without ever touching an operator. FM Essential lands in between on paper, with editable 4-operator voices, but the free app has only 10 of them until you connect a Yamaha MX.

What to look for in an FM synth app

• A real engine or samples. Sample players like King of FM sound like the hardware because they are recordings of it, but you cannot reprogram them. To make your own sounds, you need editable operators.
• Six operators or four. Six (the DX7 layout) gives the most detail and opens up decades of DX7 patches. Four (as on the DX100, TX81Z and V50, and in KQ Tixie, FM Essential and Omega) is quicker to learn and still covers bass, bells and keys.
• Patch import. For vintage sounds, check for DX7 .syx import. KQ Dixie 26 and M2DX have it. KQ Tixie’s developer states plainly that it is not DX7-compatible, though it reads TX81Z-family patches.
• AUv3 support. To play a synth inside GarageBand or AUM, it has to load as an AUv3 plug-in. KQ Dixie 26, M2DX, KQ Tixie, King of FM, FM Essential and Omega all do.
• Screen size. Six operators, each with its own envelope, is a lot to fit on a phone. If you plan to program sounds on the phone itself, a one-screen editor like Omega’s keeps every operator in view.

Once you have an app, try this first patch on any FM synth with ratio controls. Set the carrier and one modulator to ratio 1, with the modulator level at zero, which gives a plain sine. Raise the modulator level and the tone brightens toward a buzzy, sawtooth-like sound. Change the modulator ratio to 2 and it turns hollow and clarinet-like, because only odd harmonics are left. Try 3.5 and it becomes a bell, because many of the new overtones land between the note’s harmonics. Give the modulator a short decay (around 300 ms) and a low sustain, and the brightness pops at the start and then fades, which is the basic shape of an FM electric piano or pluck.

Our guide to making an FM bell sound takes that 3.5 ratio further. For synths that are not FM, see the best synth apps for iPhone.