# Pure Acid vs ButterSynth

The clearest difference is price: Pure Acid at $7.99 against ButterSynth's $19.99. Pure Acid also leads on rating (4.9 vs 4.0) and review sentiment (94% vs 59%). ButterSynth's advantage is in-app purchases (none vs 2). On ratings volume, ads, device support and iOS requirement there is nothing between them.

Pure Acid costs $7.99 and ButterSynth $19.99 up front. Pure Acid sells 2 one-off in-app purchases. ButterSynth asks for nothing beyond the download.

Pure Acid holds the better App Store score, 4.9 against 4.0. Both are backed by a comparable volume of ratings — 169 and 63 respectively. Written reviews point the same way: 94% of Pure Acid's written reviews are positive against 59% of ButterSynth's.

Pure Acid ships an update every 3 weeks, ButterSynth every 2 months. Both last shipped on October 29, 2026.

## The numbers

| Metric | Pure Acid | ButterSynth |
| --- | --- | --- |
| Price | **$7.99** | $19.99 |
| Rating | **[4.9 (169 ratings)](https://appshunter.io/ios/app/pure-acid/id1481283602/reviews)** | [4.0 (63 ratings)](https://appshunter.io/ios/app/buttersynth/id1497419006/reviews) |
| Number of ratings | **169** | 63 |
| Positive reviews | **94.1% of reviews** | 59.2% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 2 months |
| Monetization | **Free with in-app purchases** | Paid |
| Best chart rank | **#114** | — |
| Size | 44 MB | 468 MB |
| Requires iOS | **13.0** | 14.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Dmitrij Pavlov](https://appshunter.io/developer/478154322) | [Arto Vaarala](https://appshunter.io/developer/890886114) |

## What reviewers say

### Pure Acid

[App page](https://appshunter.io/ios/app/pure-acid/id1481283602)

**Currently charting:** #114 Top Paid · Music (US App Store)

This app is a high-quality bassline synthesizer and drum machine inspired by classic 80s hardware. It offers a retro analog sound with modern features for fast and fun music creation. Explore various genres with factory presets and create unique rhythms and basslines.

**Highlights:** AUv3, Ableton Link, AudioBus, IAA support, Classic bassline waveforms (Saw, Pulse), Distortion and filter LFO effects, 32-step sequencer with pattern editing, 16 independent drum parts with customizable sounds, Realtime master effects with XY-pad

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Ukrainian style color scheme | $4.99 | one-time |
| Ukrainian style app icon | $4.99 | one-time |

**What reviewers like**

- 🚀 Powerful and feature-rich
- 👍 Intuitive and easy to use
- 🎶 Excellent sound quality
- 🎛️ Great sequencing and programming capabilities
- 🔌 Seamless integration with other apps and hardware

**What reviewers complain about**

- 🐛 Occasional audio cutoff or sync issues
- 🔍 Lack of detailed documentation or tutorials
- 🔀 Limitations in pattern length and drum sequencing

**Reported bugs**

- GUI scaling issues on smaller devices
- Crashes or freezes on certain devices

**Requested features**

- Ability to import MIDI files
- Standalone drum machine mode
- Expanded drum sample library
- Knob/parameter automation recording


### 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 Pure Acid free?

Pure Acid costs $7.99, and also offers in-app purchases.

### Is ButterSynth free?

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

### Which has better reviews, Pure Acid or ButterSynth?

Pure Acid is rated higher. Pure Acid averages 4.9 out of 5 from 169 ratings, while ButterSynth averages 4.0 from 63 ratings.

### Do Pure Acid or ButterSynth have ads?

Neither Pure Acid nor ButterSynth shows ads.

### Which is updated more often, Pure Acid or ButterSynth?

Pure Acid ships an update every 3 weeks, and ButterSynth every 2 months. Most recently, Pure Acid was updated on October 29, 2026 and ButterSynth on October 29, 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.*