# AUFX vs ButterSynth

The clearest difference is price: AUFX at $4.99 against ButterSynth's $19.99. AUFX also leads on rating (4.3 vs 4.0) and iOS requirement (9.0 vs 14.0). On review sentiment, ratings volume, update cadence and ads there is nothing between them.

AUFX costs $4.99 and ButterSynth $19.99 up front. Neither carries in-app purchases, so what you see is what you pay.

AUFX holds the better App Store score, 4.3 against 4.0. Both are backed by a comparable volume of ratings — 32 and 63 respectively. Written reviews point the same way: 66% of AUFX's written reviews are positive against 59% of ButterSynth's.

AUFX ships an update every 5 months, ButterSynth every 2 months. The most recent releases landed on October 9, 2026 and October 16, 2026 respectively.

## The numbers

| Metric | AUFX | ButterSynth |
| --- | --- | --- |
| Price | **$4.99** | $19.99 |
| Rating | **[4.3 (32 ratings)](https://appshunter.io/ios/app/aufxpush/id958106165/reviews)** | [4.0 (63 ratings)](https://appshunter.io/ios/app/buttersynth/id1497419006/reviews) |
| Number of ratings | 32 | **63** |
| Positive reviews | **65.8% of reviews** | 59.2% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 2 months** |
| Monetization | Paid | Paid |
| Size | 5 MB | 468 MB |
| Requires iOS | **9.0** | 14.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Kymatica AB](https://appshunter.io/developer/522046659) | [Arto Vaarala](https://appshunter.io/developer/890886114) |

## What reviewers say

### AUFX

[App page](https://appshunter.io/ios/app/aufxpush/id958106165)

This app offers a versatile stereo dynamics processor with advanced features like a noise gate, compressor/expander, and limiter. It allows for a wide range of audio manipulation, from subtle adjustments to extreme effects, with external side-chain capabilities and high-quality DSP.

**Highlights:** Stereo dynamics processor, Noise gate, Compressor/expander, External side-chain input, Lookahead limiter, High quality 32-bit DSP

**Features:** Vision Pro support

**In-app purchases:** none


### ButterSynth

[App page](https://appshunter.io/ios/app/buttersynth/id1497419006)

This powerful synthesizer app offers a hybrid approach, combining wavetable, FM, and sample-based synthesis. Create unique sounds with a vast sonic range, advanced modulation, and a built-in effects rack. It caters to both experienced sound designers and beginners with extensive presets.

**Highlights:** Hybrid 6-oscillator synthesis (wavetable, FM, sample), Built-in wavetable editor, FM engine with 4 operators, Sample and Granulator engines, 32-slot modulation matrix, Internal FX rack with 16 modules, Extensive preset library

**Features:** Vision Pro support

**In-app purchases:** none

**What reviewers like**

- ✨ Deep sound design capabilities
- 🎛️ Versatile modulation matrix
- 🔊 Great sound quality
- 💡 Innovative wavetable generator
- 🌟 Serum-like experience

**What reviewers complain about**

- 📱 Fiddly on small screens
- 🐛 Crashes frequently
- 🐛 Disappears in Cubasis
- 🐛 Spikes CPU usage
- 🐛 Crashes on patch change

**Reported bugs**

- App crashing with AUM
- Disappears in Cubasis randomly
- Crashes all the time inside Logic
- Changing a patch spikes CPU to 99%
- Crashes on every patch change

**Requested features**

- MPE popup possible on top of the auv3
- Button to hide built-in keyboard
- Buffer size option
- Additional MIDI mappings (e.g., arpeggiator toggle)
- Sustain pedal support


## Frequently asked questions

### Is AUFX free?

AUFX costs $4.99, with no in-app purchases.

### Is ButterSynth free?

ButterSynth costs $19.99, with no in-app purchases.

### Which has better reviews, AUFX or ButterSynth?

AUFX is rated higher. AUFX averages 4.3 out of 5 from 32 ratings, while ButterSynth averages 4.0 from 63 ratings.

### Do AUFX or ButterSynth have ads?

Neither AUFX nor ButterSynth shows ads.

### Which is updated more often, AUFX or ButterSynth?

AUFX ships an update every 5 months, and ButterSynth every 2 months. Most recently, AUFX was updated on October 9, 2026 and ButterSynth on October 16, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*