---
type: AI Model
id: separate-stems-api
title: Audio Stem Separation API
provider: Pixazo
description: "Split an audio or video file into isolated stems. Two-stem mode returns vocals and no_vocals — the pairing dubbing needs, so replacing speech no longer destroys the music bed. Four-stem mode returns vocals, drums, bass and other for remixing. Pass an audio_url (a video URL is fine; the audio is extracted server-side), poll the request, then download the stems as MP3 or WAV."
resource: https://www.pixazo.ai/models/separate-stems-api
docs_url: https://www.pixazo.ai/models/separate-stems-api
latest_version: v1
tags:
  - separate-stems
  - pixazo
variants:
  - id: audio-separate-stems-v1
    name: Audio Stem Separation 1.0
    version: 1.0
    capabilities:
      - Separate Stems
timestamp: 2026-08-26T14:31:04.421Z
---

# Audio Stem Separation API

> Provider: **Pixazo**
> Source: https://www.pixazo.ai/models/separate-stems-api

Split an audio or video file into isolated stems. Two-stem mode returns vocals and no_vocals — the pairing dubbing needs, so replacing speech no longer destroys the music bed. Four-stem mode returns vocals, drums, bass and other for remixing. Pass an audio_url (a video URL is fine; the audio is extracted server-side), poll the request, then download the stems as MP3 or WAV.

## Audio Stem Separation 1.0

### Separate Stems

## Base URL

```
https://gateway.pixazo.ai/audio-tools/v1/separate-stems
```

## Authentication

All requests require an API key passed via header.

**Pricing:** Billed at **$0.005 per second of input audio** — measured on the file you submit, not on the stems returned. A 60-second track costs $0.30. Accepts audio _or_ video; for video the audio is extracted server-side and you are billed on its duration.

**Rounding:** billing is per second but always rounds **up to a whole second** — a 5.06-second source bills as 6 seconds. The shortest billable job is 1 second.

**Retries:** this is an asynchronous job on shared encoding capacity, so a request can occasionally come back `processing_failed` or take much longer than usual. These are transient and succeed on a retry, and a failed job is **never charged** — the wallet hold is released. If you chain these tools, retry a failed step rather than failing the whole pipeline.

Header

Type

Required

Description

Ocp-Apim-Subscription-Key

string

Yes

Your API subscription key

## Audio Separate Stems generate request

## Request Code

HTTP Python JavaScript cURL

```
POST https://gateway.pixazo.ai/audio-tools/v1/separate-stems
Content-Type: application/json
Cache-Control: no-cache
Ocp-Apim-Subscription-Key: YOUR_API_KEY

{
  "audio_url": "https://api-assets.pixazo.ai/media/audio-tools-example.mp3",
  "stems": "two",
  "output_format": "mp3"
}
```

```
import requests

url = "https://gateway.pixazo.ai/audio-tools/v1/separate-stems"
headers = {
    "Content-Type": "application/json",
    "Cache-Control": "no-cache",
    "Ocp-Apim-Subscription-Key": "YOUR_API_KEY"
}
data = {
    "audio_url": "https://api-assets.pixazo.ai/media/audio-tools-example.mp3",
    "stems": "two",
    "output_format": "mp3"
}

response = requests.post(url, json=data, headers=headers)
print(response.json())
```

```
const url = "https://gateway.pixazo.ai/audio-tools/v1/separate-stems";
const headers = {
  "Content-Type": "application/json",
  "Cache-Control": "no-cache",
  "Ocp-Apim-Subscription-Key": "YOUR_API_KEY"
};
const data = {
  "audio_url": "https://api-assets.pixazo.ai/media/audio-tools-example.mp3",
  "stems": "two",
  "output_format": "mp3"
};

fetch(url, {
  method: "POST",
  headers: headers,
  body: JSON.stringify(data)
})
.then(response => response.json())
.then(data => console.log(data));
```

```
curl -X POST "https://gateway.pixazo.ai/audio-tools/v1/separate-stems" \
  -H "Content-Type: application/json" \
  -H "Cache-Control: no-cache" \
  -H "Ocp-Apim-Subscription-Key: YOUR_API_KEY" \
  --data-raw '{
    "audio_url": "https://api-assets.pixazo.ai/media/audio-tools-example.mp3",
    "stems": "two",
    "output_format": "mp3"
  }'
```

## Output

```
{
  "request_id": "audio-separate-stems_019dxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
  "status": "QUEUED",
  "polling_url": "https://gateway.pixazo.ai/v2/requests/status/audio-separate-stems_019dxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
}
```

[Try Now](https://api.pixazo.ai/api-details#api=audio-tools&operation=separate-stems)

## Webhook (Optional)

Add the `X-Webhook-URL` header to your generate request to receive a POST callback instead of polling.

```
X-Webhook-URL: https://your-server.com/webhook/callback
```

## Request Parameters - Audio Separate Stems generate request

Parameter

Required

Type

Default

Allowed values / range

Description

audio\_url

Yes

string

—

HTTP(S) URL; ≤ 500 MB

Publicly reachable HTTP(S) URL of an audio or video file. For video the audio track is extracted server-side. Maximum file size: 500 MB.

stems

No

enum

"two"

"two", "four"

How many stems to split the track into. "two" returns vocals + no\_vocals (dialogue vs the music-and-effects bed — the dubbing case, and roughly 2x faster); "four" returns vocals, drums, bass and other.

output\_format

No

enum

"mp3"

"mp3", "wav"

Encoding of every returned stem. "mp3" is 192 kbps; "wav" is uncompressed (lossless, larger files).

## Example Request

```
{
  "audio_url": "https://api-assets.pixazo.ai/media/audio-tools-example.mp3",
  "stems": "two",
  "output_format": "mp3"
}
```

## Response

```
{
  "request_id": "audio-separate-stems_019dxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
  "status": "QUEUED",
  "polling_url": "https://gateway.pixazo.ai/v2/requests/status/audio-separate-stems_019dxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
}
```

## Request Headers

Header

Value

Content-Type

application/json

Cache-Control

no-cache

Ocp-Apim-Subscription-Key

YOUR\_API\_KEY

## Response Handling

Common status codes.

Code

Meaning

202

Accepted — Request queued

400

Bad Request

401

Unauthorized

402

Insufficient Balance

403

Forbidden

429

Too Many Requests

500

Internal Server Error

## Error Responses

Queue system errors and model validation errors.

### Queue System Errors

```
// 402 — Insufficient balance
{
  "error": "Insufficient Balance",
  "message": "Your wallet does not have enough balance."
}
```

```
// 400 — Model not found
{
  "error": "Model not found",
  "message": "Model 'audio-separate-stems' not found or is disabled"
}
```

### Error via Status/Webhook

```
{
  "request_id": "audio-separate-stems_019dxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
  "status": "ERROR",
  "model_id": "audio-separate-stems",
  "error": "Description of the error",
  "output": null
}
```

## Retrieving Results

Poll the universal status endpoint to check progress and retrieve results.

### Endpoint

```
GET https://gateway.pixazo.ai/v2/requests/status/{request_id}
Ocp-Apim-Subscription-Key: YOUR_API_KEY
```

## cURL Example

```
curl -H "Ocp-Apim-Subscription-Key: YOUR_API_KEY" \
  "https://gateway.pixazo.ai/v2/requests/status/audio-separate-stems_019dxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
```

## Response (Completed)

```
{
  "request_id": "audio-separate-stems_019dxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
  "status": "COMPLETED",
  "model_id": "audio-separate-stems",
  "error": null,
  "output": {
    "media_url": [
      "https://pub-582b7213209642b9b995c96c95a30381.r2.dev/v1/audio-separate-stems_019dxxxx/vocals.mp3",
      "https://pub-582b7213209642b9b995c96c95a30381.r2.dev/v1/audio-separate-stems_019dxxxx/no_vocals.mp3"
    ],
    "media_type": "audio/mpeg"
  },
  "created_at": "2026-03-31T10:00:00.000Z",
  "updated_at": "2026-03-31T10:00:15.000Z",
  "completed_at": "2026-03-31T10:00:15.000Z"
}
```

## Response Fields

Field

Type

Description

request\_id

string

Unique request identifier

status

string

QUEUED, PROCESSING, COMPLETED, FAILED, or ERROR

model\_id

string

Model that processed the request

error

string|null

Error message if failed

output.media\_url

array

URLs to generated media (R2 CDN)

output.media\_type

string

MIME type of the output

created\_at

string

When request was created

completed\_at

string

When request completed

polling\_url

string

Status URL (initial response only)

## Status Values

Status

Description

QUEUED

Request accepted, waiting to be processed

PROCESSING

Being processed by the model

COMPLETED

Done — output contains the result

FAILED

Failed — check error field

ERROR

System error — not charged

## Status Flow

```
QUEUED → PROCESSING → COMPLETED
                    → FAILED
                    → ERROR
```

## Typical Workflow

1.  **Send a generate request** to the API endpoint
2.  **Save the `request_id`** from the response
3.  **Poll** every 5-10 seconds: `GET /v2/requests/status/{request_id}`
4.  **When `status` is `"COMPLETED"`**, download from `output.media_url`

**Tip:** Use `X-Webhook-URL` header to get a callback instead of polling.