AudioKit Synth One Synthesizer 4+

Feature-packed Pro Synthesizer

AudioKit Pro

    • 4.9 • 25.1K Ratings
    • Free



REQ: iPhone 6 or bigger ** Synth One is Awesome & Free. Includes 400+ sounds by producers for Kanye, Rihanna, M83, Tycho, & more.. ** App of the Year, Runner Up **

“A big step forward for mobile music” - CDM (Create Digital Music)
"Groundbreaking iOS synth app" - Cult of Mac
"Must-download for every iPad owner" - MacBreak

*** "2018 App of the Year, Runner up" – ***
*** “Best iOS Music Apps of 2018” – Cult of Mac ***
*** “Best of 2018: iOS Apps for Musicians” – Ask.Audio ***

"AudioKit Synth One is a free feature-packed synth for your iPad, including 300+ presets created by professional sound designers behind M83, Tycho, and Rihanna" - Engadget

*** “Best Music Apps of 2018” – Music Radar ***


*** Optimized for newer iPads & iPhones for best performance.
Note: Requires iPhone 6 or higher screen size. App will not work on older iPhone 5/SE/Touch devices

"A Stunning Endeavor... Sounds Amazing!"
- Francis Preve, Electronic Musician Magazine

“Amazing & Brilliant… Sounds fantastic!”
– The Sound Test Room

"A great example of human endeavor"
- Gaz Williams, Sonic State

"Sounds amazing... the start of something huge."
- Ask.Audio

AudioKit Synth One is the first completely free & open-source professional iOS Synthesizer app in history. No Ads. No IAP. It will always be free.

"Powerful... Awesome" -
"An amazing synth app for your iPad that’s as close to sorcery as it gets" - GarageBand Guide
"Must Have iOS Synthesizer" - Synth Anatomy
"Synth One is a robust piece of free software" - The Verge
"It WOWS you... immediately fun to start tweaking!" - discchord
"A damn fine synth" - Computer Music Magazine
"Open-source and seriously powerful" - Future Music Magazine
"A labour of love that everyone can enjoy" - Music Radar
"Extremely exciting passion project" - Music Tech Magazine
"Make your own imposing synthesizer sounds and teach yourself the basics of music production" - Lifehacker

Learn more:

Created by over 100+ volunteers around the world (including sound designers for M83, Rihanna, Kanye West, Neon Trees, Mike Posner, Tycho, and more), this app includes MIDI support (play it with a MIDI keyboard or controller), sequencer, vintage-inspired analog filters, expressive arpeggiators, warm analog delays, and, over 300+ presets to get you started!

Email us your music & bugs:

This synthesizer is completely free, fully functional, and ad-free. There are no IAP or anything to buy -- It’s the ultimate free iPad music instrument app!

• Hybrid Analog/FM Poly Synthesizer
• Over 300+ Presets crafted by famous sound designers
• Audiobus 3 & Inter-app Audio (IAA)
• Ableton Link
• Five Oscillators (2 DCO, FM, Sub, Noise)
• 2 LFOs with over a dozen routing possibilities
• Vintage-Style 16-Step Sequencer
• Classic poly arpeggiator
• MIDI in (Control with a MIDI Keyboard or AudioBus/IAA)
• Touchable ADSR Envelopes for Amp & Filter
• FM Oscillator w/ Mod
• Mono glide and legato
• Dedicated Sine/Square -12/24 Sub Osc
• 4-Pole Vintage Low-Pass Filter
• High-Pass/Band Pass Filters
• Beautiful Costello Reverb
• Multi-tap (ping-pong) delay
• TouchPads
• Preset & Bank Import/Export & More…

BONUS: Full Source code is now available!

Plus, it’s completely open-source. Use the code to learn how to build your own synth app or modify the app yourself!


"Amazing noises that will make your ears squee with glee" - Stuff Magazine
"Pick of the Week" - MacBreak

On the roadmap:
• MPE Support (Play w/ a Roli Seaboard)
• AUv3 Plug-in support

What’s New

Version 1.8.1

THANKS! FREE Learning Synthesis & Synth One manual in this update!
+ Full Free Synth Tutorial iBook by award-winning sound designer Francis Preve
+ Preset bank called "Synth Tutorials" are a companion to that book
+ We are all volunteer musicians & coders. Thanks for your help!
+ Download is in the "About" page. Or you can find it on the Books app and iTunes:

Please note that we all are volunteers. We are all musician/developers who love making apps.

Together we can change the world.

We love hearing your music! Send it to us. For friendly conversation or to say hello, please email

The full & complete source code is available:

Ratings and Reviews

4.9 out of 5
25.1K Ratings

25.1K Ratings


Best synth (I tried the others, they compete for 2nd)

This app is exactly what it says, and then some. It offers a pretty nice set of effects on top of the oscillators and sequencer. It’s also very user friendly. It took me all of 20 minutes to figure out how everything worked, and I am a complete novice at producing. If you are looking for a portable synth to make some sounds on the go, you just found the best one. I searched through the App Store and tried others; Synth One offers so many more options, including saving your work to presets and exporting!

Suggestion to the developers: just a thought for future expansion of the app, can we get additional base waveforms to work with? Triangle, sawtooth, square, and a low duty cycle square are nice, but the addition of sine waves and other, more complex wave forms would offer some nice new possibilities. Also, being able to add extra filters (that is, have 2, 3, or more filters at once) would be a very nice feature for the future. Lastly, having more than 2 oscillators would be great. There’s a lot you can do with 2, but three brings in a whole new dimension to things.

=jD ,

Please add DOTTED-8th-NOTE to Delay's Tempo Sync

This thing is almost there... So good and so fun! The one missing "feature of a feature" that I feel is quite common, even on stomp-box delays and in various music apps is a setting for a dotted eighth note delay time (an 8th plus a 16th note). This would allow much easier creation of rhythmic effects on a 16th-note pulse that are the backbone of tracks from Pink Floyd (ABITW Pt. 1 and lots more, on The Wall and after) to Kraftwerk & The Orb all the way up to Deadmau5, LCD Soundsystem and lots of modern trap, house, hip-hop, jungle, w. coast bass, techno, and other genres. Right now the app has all the triplets, which is cool, but not the same thing as the dotted effect. Synth One could consider adding it for 16th and/or 1/4 note intervals but they're less important. Your users will get a lot of mileage with just dotted-Eighth making a 16th-note rhythm unless they are tempo extremists. =) One can come close, setting delay time without using Tempo Sync, but the control is honestly jumpy and hard to finesse, and if you change the synth global tempo, it's wrong again. I humbly offer the last otherwise well-deserved star on this review in return. (It's open source; I suppose I should just learn how it all works and add it myself LOL.)

TBMisamazing ,

Absolutely phenomenal

This synth sounds amazing, looks amazing, has more features than you would expect, and it’s free!! This quickly became a favorite synth of mine; I’m more pleased with it than apps I’ve paid $20+ for. I’m running it on an Air 1 and haven’t run into any performance problems with this.

Some features I really dig are the oscilloscope, the tuning controls, and the effects. It’s cool being able to see your sounds in real-time and not many synths—hardware or software—have that feature. The tuning page is really inspiring because you can get some nice variations while using the sequencer. And the effects sound absolutely beautiful. I also enjoy the ability to scroll through the different pages while playing the onscreen keyboard.

That’s not where the awesomeness of this app ends though. I cannot speak highly enough of what Matt and the rest of the team have pulled off here. To me, the greatness of a synthesizer is judged by how immersive the playing experience is, and Synth One delivers. You can quickly get lost in playing this because it is just that good. If you have an iPad, you need this app.

App Privacy

The developer, AudioKit Pro, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More

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