---
license: apache-2.0
language:
- multilingual
tags:
- whisper
- automatic-speech-recognition
- asr
- speech
- onnx
- onnxruntime
- sherpa-onnx
- soniqo
base_model: openai/whisper-medium
library_name: onnxruntime
pipeline_tag: automatic-speech-recognition
---

# Whisper Medium - ONNX

Official OpenAI Whisper medium checkpoint exported as ONNX encoder/decoder graphs for `speech-core` and sherpa-onnx-compatible runtimes.

> Part of the [soniqo.audio](https://soniqo.audio) speech toolkit. This is the ONNX Runtime bundle used by `speech-core` for server, desktop, and Android-style runtimes; the graphs remain sherpa-onnx compatible. Browse ONNX bundles in the [soniqo ONNX collection](https://huggingface.co/collections/soniqo/onnx-6a1c0ae64587a78f8e8b9b96).

## Model

| | |
|---|---|
| Source | [openai/whisper-medium](https://huggingface.co/openai/whisper-medium) |
| Export format | ONNX for sherpa-onnx |
| Variants | FP32, INT8, FP16 |
| Runtime | speech-core `OnnxWhisperStt` / ONNX Runtime; sherpa-onnx compatible |
| Total artifact size | 5277.42 MiB |

The FP16 graphs use external `*.onnx.data` files. Large-style bundles also use external FP32 `*.weights` files. Keep external-data files beside their matching `.onnx` files.

## Files

| File | Size | Description |
|---|---:|---|
| `medium-decoder.fp16.onnx` | 1.62 MB | Whisper decoder graph |
| `medium-decoder.fp16.onnx.data` | 774.93 MB | External tensor data for the adjacent ONNX graph |
| `medium-decoder.int8.onnx` | 544.56 MB | Whisper decoder graph |
| `medium-decoder.onnx` | 1551.82 MB | Whisper decoder graph |
| `medium-encoder.fp16.onnx` | 0.44 MB | Whisper encoder graph |
| `medium-encoder.fp16.onnx.data` | 682.02 MB | External tensor data for the adjacent ONNX graph |
| `medium-encoder.int8.onnx` | 356.81 MB | Whisper encoder graph |
| `medium-encoder.onnx` | 1364.44 MB | Whisper encoder graph |
| `medium-tokens.txt` | 0.78 MB | Tokenizer tokens for speech-core and sherpa-onnx-compatible runtimes |

## Usage

Use with [speech-core](https://github.com/soniqo/speech-core)'s native ONNX Whisper runtime:

```cpp
#include <speech_core/models/onnx_whisper_stt.h>

speech_core::OnnxWhisperStt stt(
    "medium-encoder.int8.onnx",
    "medium-decoder.int8.onnx",
    "medium-tokens.txt");

auto result = stt.transcribe(audio, length, 16000);
```

The same encoder/decoder/token files can also be loaded by sherpa-onnx:

```python
import sherpa_onnx

recognizer = sherpa_onnx.OfflineRecognizer.from_whisper(
    encoder="medium-encoder.fp16.onnx",
    decoder="medium-decoder.fp16.onnx",
    tokens="medium-tokens.txt",
    language="en",
    task="transcribe",
    provider="cpu",
)
```

## Benchmarks

This repository ships the exported model artifacts. Full published WER/RTF is currently available for the turbo bundle; run the benchmark command above for local numbers on this variant.

## Links

- Website: [soniqo.audio](https://soniqo.audio)
- Speech Core: [github.com/soniqo/speech-core](https://github.com/soniqo/speech-core)
- Docs: [soniqo.audio/speech-core](https://soniqo.audio/speech-core)
- Blog: [soniqo.audio/blog](https://soniqo.audio/blog)