curl -X POST 'https://api.elevenlabs.io/v1/similar-voices' \
  -H "xi-api-key: $ELEVENLABS_API_KEY" \
  -F 'audio_file=@sample.bin' \
  -F 'similarity_threshold=0' \
  -F 'top_k=0'

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

> Get Similar Library Voices

## 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/similar-voices' \
  -H "xi-api-key: $ELEVENLABS_API_KEY" \
  -F 'audio_file=@sample.bin' \
  -F 'similarity_threshold=0'

## Parameters
| Name | In | Type | Required | Description |
| :--- | :--- | :--- | :--- | :--- |
| audio_file | body | string | No | Request body field audio_file. |
| similarity_threshold | body | number | No | Threshold for voice similarity between provided sample an... |
| top_k | body | integer | No | Number of most similar voices to return. If similarity_th... |

## Response (200 OK)
{"has_more":false,"total_count":0}

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

POST

/v1/similar-voices

ElevenLabs API

Get Similar Library Voices

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
→ 215 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/similar-voices' \  -H "xi-api-key: $ELEVENLABS_API_KEY" \  -F 'audio_file=@sample.bin' \  -F 'similarity_threshold=0' \  -F 'top_k=0'

Get a free ElevenLabs API key → sponsored

Parameters

Name	In	Type	Required	Description
audio_file	body	string	No	Request body field audio_file.
similarity_threshold	body	number	No	Threshold for voice similarity between provided sample and library voices. Values range from 0 to 2. The smaller the value the more similar voices will be returned.
top_k	body	integer	No	Number of most similar voices to return. If similarity_threshold is provided, less than this number of voices may be returned. Values range from 1 to 100.

Response 200 OK

{
  "has_more": false,
  "total_count": 0,
  "voices": [
    {
      "accent": "american",
      "age": "young",
      "category": "professional",
      "cloned_by_count": 11,
      "date_unix": 1714423232,
      "description": "Perfectly calm, neutral and strong voice. Great for a young female protagonist.",
      "descriptive": "calm",
      "featured": false,
      "free_users_allowed": true,
      "gender": "Female",
      "language": "en",
      "live_moderation_enabled": false,
      "name": "Alita",
      "play_api_usage_character_count_1y": 12852,
      "preview_url": "https://storage.googleapis.com/eleven-public-prod/wqkMCd9huxXHX1dy5mLJn4QEQHj1/voices/sB1b5zUrxQVAFl2PhZFp/55e71aac-5cb7-4b3d-8241-429388160509.mp3",
      "public_owner_id": "63e84100a6bf7874ba37a1bab9a31828a379ec94b891b401653b655c5110880f",
      "rate": 1,
      "usage_character_count_1y": 12852,
      "usage_character_count_7d": 12852,
      "use_case": "characters_animation",
      "verified_languages": [
        {
          "accent": "american",
          "language": "en",
          "locale": "en-US",
          "model_id": "eleven_multilingual_v2",
          "preview_url": "https://storage.googleapis.com/eleven-public-prod/wqkMCd9huxXHX1dy5mLJn4QEQHj1/voices/sB1b5zUrxQVAFl2PhZFp/55e71aac-5cb7-4b3d-8241-429388160509.mp3"
        }
      ],
      "voice_id": "sB1b5zUrxQVAFl2PhZFp"
    }
  ]
}