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Get startedCactus vs Nexa AI: On-Device AI Inference Compared
Cactus and Nexa AI both offer on-device AI inference across LLMs, speech, and vision. Cactus differentiates with hybrid cloud routing and cross-platform SDKs for Swift, Kotlin, Flutter, and React Native. Nexa AI brings a proprietary NexaML engine built from scratch at the kernel level for peak hardware performance. Both are open source.
Cactus
Cactus is a hybrid AI inference engine for mobile devices, laptops, and edge hardware. It runs LLMs, transcription, vision, and embeddings on-device with automatic cloud fallback when confidence is low. Cactus provides sub-120ms latency, cross-platform SDKs spanning Swift, Kotlin, Flutter, React Native, Python, C++, and Rust, plus NPU acceleration on Apple devices.
Nexa AI
Nexa AI is an on-device AI platform with its proprietary NexaML engine built from scratch at the kernel level. It supports LLMs, VLMs, ASR, TTS, embeddings, and computer vision across NPU, GPU, and CPU backends. Nexa AI offers broad model support including frontier models like Qwen-3 and Gemma-3n, with SDKs for Python, Kotlin, and iOS.
Feature comparison
Performance & Latency
Cactus achieves sub-120ms on-device latency through zero-copy memory mapping and INT4/INT8 quantization. Nexa AI's NexaML engine is built from scratch for kernel-level optimizations across NPU, GPU, and CPU. Both deliver strong inference speeds, but Cactus's hybrid routing can offload to the cloud when local hardware is insufficient, avoiding quality degradation on constrained devices.
Model Support
Both platforms support major model families. Cactus runs Gemma 3/4, Qwen 3, LFM2, Whisper, Moonshine, and Parakeet with under 6% WER for transcription. Nexa AI supports GPT-OSS, Granite-4, Qwen-3, Gemma-3n, and Octopus function-calling models. Nexa AI adds TTS capabilities that Cactus does not currently offer natively.
Platform Coverage
Cactus covers iOS, Android, macOS, Linux, watchOS, and tvOS with native SDKs for Swift, Kotlin, Flutter, React Native, Python, C++, and Rust. Nexa AI supports iOS, Android, macOS, and Linux with Python and Kotlin SDKs but lacks a native Swift SDK. Cactus provides broader cross-platform reach, especially for wearable and cross-framework mobile development.
Pricing & Licensing
Both Cactus and Nexa AI are open source. Cactus is MIT licensed with an optional cloud API on usage-based pricing. Nexa AI's SDK is open source on GitHub with enterprise solutions available. For teams wanting fully free on-device inference, either option works. Cactus's cloud fallback adds a paid component only if you choose to enable it.
Developer Experience
Cactus provides a single unified API across LLM, transcription, vision, and embeddings, reducing integration complexity. Its cross-platform SDKs mean one learning curve for all targets. Nexa AI's approach targets Python and mobile developers, with its NexaML engine abstracted behind SDK calls. Cactus's hybrid routing simplifies quality assurance since low-confidence requests route to the cloud automatically.
Strengths & limitations
Cactus
Strengths
- Hybrid routing automatically falls back to cloud when on-device confidence is low
- Single unified API across LLM, transcription, vision, and embeddings
- Sub-120ms on-device latency with zero-copy memory mapping
- Cross-platform SDKs for Swift, Kotlin, Flutter, React Native, Python, C++, and Rust
- NPU acceleration on Apple devices for significantly faster inference
- Up to 5x cost savings on hybrid inference compared to cloud-only
Limitations
- Newer project compared to established frameworks like TensorFlow Lite
- Qualcomm and MediaTek NPU support still in development
- Cloud fallback requires API key configuration
Nexa AI
Strengths
- Proprietary NexaML engine built from scratch for peak performance
- Broad model support including latest frontier models
- Comprehensive coverage of AI modalities (LLM, VLM, ASR, TTS, CV)
- NPU acceleration across multiple hardware backends
Limitations
- No built-in hybrid cloud/on-device routing
- No native Swift SDK for iOS development
- Younger ecosystem compared to TensorFlow Lite or CoreML
- Limited wearable device support
The Verdict
Choose Cactus if you need hybrid cloud routing, broad cross-platform coverage including Flutter and React Native, or a unified API across multiple AI modalities. Choose Nexa AI if you want a kernel-optimized engine with TTS support and are building primarily for mobile or Python environments. Both are strong open-source options. Cactus edges ahead for teams needing guaranteed quality through cloud fallback and the widest SDK support.
Frequently asked questions
Is Cactus or Nexa AI better for iOS development?+
Cactus offers a native Swift SDK with NPU acceleration on Apple devices, while Nexa AI provides iOS support but lacks a dedicated Swift SDK. For Swift-first iOS projects, Cactus has a more streamlined integration path.
Do Cactus and Nexa AI support speech-to-text?+
Yes. Cactus supports Whisper, Moonshine, and Parakeet models achieving under 6% WER. Nexa AI supports ASR models on-device. Both handle real-time transcription, but Nexa AI also offers text-to-speech which Cactus does not.
Which has better model performance on mobile devices?+
Both optimize for mobile. Nexa AI's NexaML engine targets kernel-level performance. Cactus uses zero-copy memory mapping and INT4/INT8 quantization for sub-120ms latency. Cactus adds hybrid routing so quality never drops below a threshold.
Are Cactus and Nexa AI free to use?+
Both are open source and free for on-device inference. Cactus is MIT licensed with an optional paid cloud API. Nexa AI's SDK is open source with enterprise plans available for advanced features.
Can I use Cactus or Nexa AI in a React Native app?+
Cactus offers a React Native SDK for direct integration. Nexa AI does not currently provide a React Native SDK, so you would need to build a native bridge yourself.
Which platform has better NPU acceleration?+
Nexa AI supports NPU, GPU, and CPU backends broadly. Cactus currently supports Apple Neural Engine with Qualcomm NPU planned. For Android NPU acceleration today, Nexa AI has a wider hardware reach.
Try Cactus today
On-device AI inference with automatic cloud fallback. One unified API for LLMs, transcription, vision, and embeddings across every platform.