# Caustic vs AudioKit Digital D1 Synth

The clearest difference is price: AudioKit Digital D1 Synth at Free against Caustic's $9.99. AudioKit Digital D1 Synth also leads on rating (4.8 vs 3.5) and update cadence (every 3 weeks vs every 4 months). Caustic's advantage is in-app purchases (none vs 6) and ads (none vs shown).

AudioKit Digital D1 Synth is free to download; Caustic costs $9.99 up front. AudioKit Digital D1 Synth sells 6 in-app purchases, starting at $4.99 per 7 days. Caustic asks for nothing beyond the download.

AudioKit Digital D1 Synth holds the better App Store score, 4.8 against 3.5. That said, the two scores are not equally well evidenced: AudioKit Digital D1 Synth has 2K ratings behind it against 176, so its average is the more settled of the two. Written reviews point the same way: 58% of Caustic's written reviews are positive against 76% of AudioKit Digital D1 Synth's.

Caustic ships an update every 4 months, AudioKit Digital D1 Synth every 3 weeks. The most recent releases landed on October 16, 2026 and October 13, 2026 respectively.

## The numbers

| Metric | Caustic | AudioKit Digital D1 Synth |
| --- | --- | --- |
| Price | $9.99 | **Free** |
| Rating | [3.5 (176 ratings)](https://appshunter.io/ios/app/caustic/id775735447/reviews) | **[4.8 (2K ratings)](https://appshunter.io/ios/app/audiokit-digital-d1-synth/id1436905540/reviews)** |
| Number of ratings | 176 | **2K** |
| Positive reviews | 57.8% of reviews | **76.1% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 4 months | **Every 3 weeks** |
| Monetization | **Paid** | Subscription |
| Size | 52 MB | 636 MB |
| Requires iOS | **7.0** | 13.0 |
| Devices | **iPhone, iPad, iPod** | iPad |
| Age rating | 4+ | 4+ |
| Developer | [Rejean Poirier](https://appshunter.io/developer/775735450) | [Audiobus Pty Ltd](https://appshunter.io/developer/672585101) |

## What reviewers say

### Caustic

[App page](https://appshunter.io/ios/app/caustic/id775735447)

Create music with a virtual synthesizer and sampler rig. Build your sound by adding up to 14 machines, including synths and drum machines. Features a mixer, effects, and a song sequencer for real-time audio production.

**Highlights:** Virtual analog subtractive synthesizer, Multi-sample wave synthesizer, Sampling drum machine, Effects rack with 20 effect types, Mixer desk with EQ and effects, Song sequencer, AudioBus and AudioCopy/Paste support

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none

**What reviewers like**

- 🚀 Powerful and feature-rich
- 👍 Intuitive workflow
- 🎨 Excellent sound quality
- 💸 Great value for money

**What reviewers complain about**

- 🐛 Compatibility issues with newer iOS versions
- 🔇 No Bluetooth audio support
- 📁 Difficulty accessing/exporting files
- 🔧 Needs more updates and bug fixes

**Reported bugs**

- Crashes and freezes on newer iPhones
- Interface scaling problems on larger screens
- Unresponsive controls in certain scenarios

**Requested features**

- Bluetooth audio support
- Improved file management and export options
- More synth/instrument options
- Expanded effects and mixing capabilities


### AudioKit Digital D1 Synth

[App page](https://appshunter.io/ios/app/audiokit-digital-d1-synth/id1436905540)

This app is a virtual analog and PCM synthesizer for iPad, inspired by the digital synthesizers of the 80s and 90s. It offers a vast library of presets, advanced synthesis features, and built-in effects for creating rich, retro-inspired sounds.

**Highlights:** 64-voice hybrid digital poly synthesis, 1GB+ of original samples, Stand-alone, IAA, and AUv3 support, Vintage-style arp/step sequencer, 3 LFOs with fun routings, Dual independent per-layer filters, Built-in FX suite

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly premium | $4.99 | per 7 days |
| Weekly premium | $4.99 | per 7 days |
| Yearly premium | $9.99 | per year |
| Yearly premium | $9.99 | per year |
| D1 PCM Expansion-01 | Free | one-time |
| Platinum Expansion PCM EXP-01 | Free | one-time |

**What reviewers like**

- 🎨 Excellent sound quality
- 🎹 Versatile and inspiring presets
- 👍 Intuitive and user-friendly interface
- 💰 Great value for the price
- 🔥 Cutting-edge digital synthesis

**What reviewers complain about**

- 🐛 Occasional crashes and stability issues
- 🔋 High battery consumption
- 🔒 Lack of Audio Unit (AUv3) support
- 🤔 Some presets not easily usable
- 🕰️ Slow loading times in certain DAWs

**Reported bugs**

- Presets not loading correctly
- MIDI note dropouts and latency
- Crashes when used with certain DAWs
- Compatibility issues with newer iOS versions

**Requested features**

- Add Audio Unit (AUv3) support
- Improve MIDI integration and responsiveness
- Implement a built-in recording/sampling feature
- Expand preset library with more genres and styles
- Add more sound design controls and modulation options


## Frequently asked questions

### Is Caustic free?

Caustic costs $9.99, with no in-app purchases.

### Is AudioKit Digital D1 Synth free?

AudioKit Digital D1 Synth is free to download, with in-app purchases available.

### Which has better reviews, Caustic or AudioKit Digital D1 Synth?

AudioKit Digital D1 Synth is rated higher. Caustic averages 3.5 out of 5 from 176 ratings, while AudioKit Digital D1 Synth averages 4.8 from 2K ratings.

### Do Caustic or AudioKit Digital D1 Synth have ads?

AudioKit Digital D1 Synth shows ads; Caustic does not.

### Which is updated more often, Caustic or AudioKit Digital D1 Synth?

Caustic ships an update every 4 months, and AudioKit Digital D1 Synth every 3 weeks. Most recently, Caustic was updated on October 16, 2026 and AudioKit Digital D1 Synth on October 13, 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.*