curl -X POST 'https://api.elevenlabs.io/v1/music/stem-separation?output_format=mp3_22050_32' \
  -H "xi-api-key: $ELEVENLABS_API_KEY" \
  -F 'file=@sample.bin' \
  -F 'stem_variation_id=six_stems_v1' \
  -F 'sign_with_c2pa=false'

# POST /v1/music/stem-separation (ElevenLabs API)
Base URL: https://api.elevenlabs.io
Auth: xi-api-key: <ELEVENLABS_API_KEY>
Last verified: 2026-09-03

> Stem Separation

## Critical Gotchas
* Authentication uses the non-standard `xi-api-key` header, not `Authorization: Bearer`. Sending a Bearer token returns HTTP 401.
* Text-to-speech responses are raw binary audio, not JSON. Write the body to a file (`--output speech.mp3`) rather than parsing it.

## cURL
curl -X POST 'https://api.elevenlabs.io/v1/music/stem-separation?output_format=mp3_22050_32' \
  -H "xi-api-key: $ELEVENLABS_API_KEY" \
  -F 'file=@sample.bin'

## Parameters
| Name | In | Type | Required | Description |
| :--- | :--- | :--- | :--- | :--- |
| file | body | string | Yes | The audio file to separate into stems. |
| output_format | query | string | No | Output format of the generated audio.... |
| stem_variation_id | body | string | No | The id of the stem variation to use. |

## Response (200 OK)
"Binary ZIP file containing files like: vocals.mp3, drums.mp3, bass.mp3, guitar.mp3, piano.mp3, other.mp3"

---
Need an API key? Get one at https://elevenlabs.io/app/sign-up

POST

/v1/music/stem-separation

ElevenLabs API

Stem Separation

Base URL: https://api.elevenlabs.io
Auth: xi-api-key: <ELEVENLABS_API_KEY>
Last verified: 2026-09-03 · upstream hash matched

Actions

Agents: curl -H "Accept: text/markdown" this URL
→ 223 tokens · Vary: Accept

Critical gotchas

Authentication uses the non-standard xi-api-key header, not Authorization: Bearer. Sending a Bearer token returns HTTP 401.

Text-to-speech responses are raw binary audio, not JSON. Write the body to a file (--output speech.mp3) rather than parsing it.

cURL

curl -X POST 'https://api.elevenlabs.io/v1/music/stem-separation?output_format=mp3_22050_32' \  -H "xi-api-key: $ELEVENLABS_API_KEY" \  -F 'file=@sample.bin' \  -F 'stem_variation_id=six_stems_v1' \  -F 'sign_with_c2pa=false'

Get a free ElevenLabs API key → sponsored

Parameters

Name	In	Type	Required	Description
output_format	query	string	No	Output format of the generated audio. Formatted as codec_sample_rate_bitrate. So an mp3 with 22.05kHz sample rate at 32kbs is represented as mp3_22050_32. MP3 with 192kbps bitrate requires you to be subscribed to Creator tier or above. PCM with 44.1kHz sample rate requires you to be subscribed to Pro tier or above. Note that the μ-law format (sometimes written mu-law, often approximated as u-law) is commonly used for Twilio audio inputs.
file	body	string	Yes	The audio file to separate into stems.
stem_variation_id	body	string	No	The id of the stem variation to use.
sign_with_c2pa	body	boolean	No	Whether to sign the generated song with C2PA. Applicable only for mp3 files.

Response 200 OK

"Binary ZIP file containing files like: vocals.mp3, drums.mp3, bass.mp3, guitar.mp3, piano.mp3, other.mp3"