“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

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

*** "2018 App of the Year, Runner up" – ***


*** 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 1.0.1

Thanks everyone! Lots of NICE upgrades in this one:
+ NOTE: iPhone 6/7/8 users with the view/sides cutoff – Do you have Zoom On in your iPhone? In your phone, try going to "Settings" > "Display & Brightness" and change zoom to "Standard". And, make sure Zoom is turned off in general accessibility. That will probably fix it for you. Good luck! :)

UPDATES by Lord of Microtonality / AudioKit team-member Marcus Hobbs:
• AudioKit TuneUp: The Tuning Panel now has a “back button” that will fast-switch back to the app that tuned up the synth without navigating to iOS. You can use apps such as "Wilsonic" to create tunings that will load into Synth One. Search for free app "Wilsonic" in the app store. This way, you can create scales & share micro-tunings between apps.

You have been asking for these updates for awhile, they're finally here:
• The Sequencer Panel now has a beat “Divisions” knob that scales the arpeggiator/sequencer tempo from 1/64th triplets to 8 bars

• The Arpeggiator+Sequencer will now start when you press a key making it easy to perform with other instruments.

• The Envelopes Panel has a knob for ADSR Pitch Tracking. The higher the value the more quiet high notes become. This is useful for presets where the high notes are as loud or louder than bass notes.

• The Keyboard bar now has a Transpose stepper (semitones)

• Fixed bug in Hidden panel (HAQ Panel) where the “Freeze Delay, Freeze Reverb, Freeze Arp Rate/Seq Pattern” buttons weren’t working properly.
Did you know Synth One has a secret hidden panel? See if you can find it ;)

Did you know the source code for Synth One is all online? And, you can contribute to the app!
New contributor, Matt Siren, is a new volunteer who added something to Synth One this week:
+ He made the Delay smoother in this update
Plus, he's got more things in the works. The AudioKit Source Code is available at
Everyone is a volunteer. Feel free to jump in!

Other updates requested by users:
+ Home bar fades out when not tapped in the area on Devices without home buttons
+ Small fixes + updates

+ Synth One & all of these upgrades will always be free. Thank you!

Please note that we all are volunteers. AudioKit does not have any sponsors or investors. We are all musician/developers who love making apps. Any help spreading the word about this app would be appreciated. The more people that know about the apps, the more musicians can enjoy them! Thank you!

For friendly conversation or to say hello, please email

Ratings and Reviews

4.9 out of 5
1.4K Ratings
1.4K Ratings

Editors' Notes

AudioKit Synth One is a wonderful example of how iPad can change the way music is made. This feature-packed synthesizer encourages play and exploration, providing plenty of fully customizable sounds to please even the most cultured of music producers. Built by musicians for musicians, AudioKit Synth One is a must-have.

Cotswold Boy ,

The best synth I've ever owned...phenomenal!

Synth One is a revelation...made by a wonderful community of lovely people who've created this amazing thing FOR FREE, in their own time. What an amazing spirit! And it's a truly remarkable piece of work: the sounds that this thing creates are absolutely astounding and are better than those from any commercial synth apps that I've ever bought, including ones I've paid upwards of thirty quid for. The functionality and control you get over sound creation are remarkable too...the big commercial houses must be dumping in their kecks at the thought of this, because this app knocks them out of the water and delivers everything you'd ever need from a synth. Awesome sounds, immense creative possibilities, stability and great design.

Massive thanks to everyone who's worked on are THE BEST!

Madyetmellow ,

Why’s it free?. Not complaining. Just Thank you 🍺😎

Had their previous app which was amazing and as soon as this was available it was an instant download. This app is incredible sounding and very easy to tweak and create your own sounds. As said in previous reviews. This app is clearly a labour of love. I would’ve happily paid for this app as a thank you for the effort the devs have put in (and it seems like a lot). Easily superior to many premium synth apps. If I can’t contribute with a purchase payment it’s only fair that I leave this review in appreciation. Very rare to see such generous developers nowadays. Download it and spread the love. You won’t regret it.

A HUGELY easy 5 ⭐️ . Still would’ve been an easy 5 star app even if it was premium priced.

Editors' Notes

AudioKit Synth One is a wonderful example of how iPad can change the way music is made. This feature-packed synthesizer encourages play and exploration, providing plenty of fully customizable sounds to please even the most cultured of music producers. Built by musicians for musicians, AudioKit Synth One is a must-have.


AudioKit Pro, LLC
66.4 MB
Requires iOS 10.3 or later. Compatible with iPhone, iPad and iPod touch.
English, French, Japanese, Portuguese, Simplified Chinese, Traditional Chinese, Turkish
Age Rating
Rated 4+
© Built with AudioKit


  • Family Sharing

    Up to six family members will be able to use this app with Family Sharing enabled.

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