SOTA OCR with Core ML and dots.ocr

Every year our hardware is a little more powerful, our models a little smarter for each parameter. In 2025, it is more feasible than ever to run truly competitive models on-device. dots.ocr, a 3B parameter OCR model from RedNote, surpasses Gemini 2.5 Pro in OmniDocBench, making OCR a truly no compromises on-device use case. Running models on-device is certainly appealing to developers: no smuggling API keys, zero cost, and no network required. However, if we want these models to run on-device, we need to be mindful of the limited compute and power budgets.

Enter the Neural Engine, Apple's custom AI accelerator that has shipped with every Apple device since 2017. This accelerator is designed for high performance whilst sipping battery power. Some of our testing has found the Neural Engine to be 12x more power efficient than CPU, and 4x more power efficient than GPU.

Whilst this all sounds very appealing, unfortunately the Neural Engine is only accessible through Core ML, Apple's closed source ML framework. Furthermore, even just converting a model from PyTorch to Core ML can present some challenges, and without a preconverted model or some knowledge of the sharp edges it can be arduous for developers. Luckily, Apple also offers MLX, a more modern and flexible ML framework that targets the GPU (not the Neural Engine), and can be used in conjunction with Core ML.

In this three part series, we will provide a reasoning trace of how we converted dots.ocr to run on-device, using a combination of CoreML and MLX. This process should be applicable to many other models, and we hope that this will help highlight the ideas and tools needed for developers looking to run their own models on-device.

To follow along, clone the repo. You'll need uv and hf installed to run the setup command:

./boostrap.sh

If you just want to skip ahead and use the converted model, you can download it here.

Conversion

Converting from PyTorch to CoreML is a two step process: