Send Audio Message

Send WhatsApp voice messages (PTT) via Evolution API

Send Audio Message

Send audio messages that appear as voice notes in WhatsApp. These are different from regular audio files and display as playable voice messages (PTT - Push-to-Talk) in the chat.

Endpoint

POST /message/sendWhatsAppAudio/:instanceName

Path Parameters

instanceName · string · required

The name of your WhatsApp instance that you created

Request Body

This endpoint supports three methods for sending audio:

1. URL: Provide a direct link to the audio file
2. Base64: Provide the base64-encoded audio content
3. File Upload: Use multipart/form-data to upload an audio file

number · string · required

The recipient’s WhatsApp number in international format (without + symbol)

Example: 5511999999999 for a Brazilian number

audio · string · required

The audio content as a URL or base64 string (not required when using file upload)

Examples:

• URL: https://example.com/audio.mp3
• Base64: data:audio/mpeg;base64,SUQzBAAAAAAAI1RTU0UAAAA...

delay · integer

Delay before sending the message in milliseconds

Example: 1000 for 1 second delay

quoted · object

Quote a previous message by providing its key and message object

encoding · boolean

Enable audio encoding for better compatibility

Default: false

Response

key · object

Message key information

message · object

The sent message object containing the audio message data

messageTimestamp · string

Unix timestamp when the message was sent

status · string

Message status (e.g., “PENDING”, “SENT”)

Code Examples

cURL - URL

curl -X POST https://your-api-url.com/message/sendWhatsAppAudio/my-instance \
  -H "Content-Type: application/json" \
  -H "apikey: YOUR_API_KEY" \
  -d '{
    "number": "5511999999999",
    "audio": "https://example.com/voice-note.mp3"
  }'

curl -X POST https://your-api-url.com/message/sendWhatsAppAudio/my-instance \
  -H "apikey: YOUR_API_KEY" \
  -F "number=5511999999999" \
  -F "file=@/path/to/audio.mp3"

const response = await fetch('https://your-api-url.com/message/sendWhatsAppAudio/my-instance', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'apikey': 'YOUR_API_KEY'
  },
  body: JSON.stringify({
    number: '5511999999999',
    audio: 'https://example.com/voice-note.mp3'
  })
});

const data = await response.json();
console.log(data);

const formData = new FormData();
formData.append('number', '5511999999999');
formData.append('file', audioFileInput.files[0]);

const response = await fetch('https://your-api-url.com/message/sendWhatsAppAudio/my-instance', {
  method: 'POST',
  headers: {
    'apikey': 'YOUR_API_KEY'
  },
  body: formData
});

const data = await response.json();
console.log(data);

import requests

url = 'https://your-api-url.com/message/sendWhatsAppAudio/my-instance'
headers = {
    'Content-Type': 'application/json',
    'apikey': 'YOUR_API_KEY'
}
payload = {
    'number': '5511999999999',
    'audio': 'https://example.com/voice-note.mp3'
}

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

import requests

url = 'https://your-api-url.com/message/sendWhatsAppAudio/my-instance'
headers = {
    'apikey': 'YOUR_API_KEY'
}
data = {
    'number': '5511999999999'
}
files = {
    'file': open('/path/to/audio.mp3', 'rb')
}

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

<?php
$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => 'https://your-api-url.com/message/sendWhatsAppAudio/my-instance',
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_CUSTOMREQUEST => 'POST',
  CURLOPT_POSTFIELDS => json_encode([
    'number' => '5511999999999',
    'audio' => 'https://example.com/voice-note.mp3'
  ]),
  CURLOPT_HTTPHEADER => [
    'Content-Type: application/json',
    'apikey: YOUR_API_KEY'
  ],
]);

$response = curl_exec($curl);
curl_close($curl);
echo $response;
?>

Advanced Examples

Send audio from URL

{
  "number": "5511999999999",
  "audio": "https://example.com/voice-message.mp3"
}

Send audio with base64 encoding

{
  "number": "5511999999999",
  "audio": "data:audio/mpeg;base64,SUQzBAAAAAAAI1RTU0UAAAA...",
  "encoding": true
}

Send audio as reply to message

{
  "number": "5511999999999",
  "audio": "https://example.com/voice-note.mp3",
  "quoted": {
    "key": {
      "id": "BAE5F2D3E4F5A6B7",
      "remoteJid": "[e-mail]",
      "fromMe": false
    },
    "message": {
      "conversation": "Original message"
    }
  }
}

Audio Format Guidelines

For best compatibility with WhatsApp voice messages, use the following formats:

Recommended Formats

• Format: MP3, OGG (Opus codec), AAC
• Sample rate: 16kHz or 48kHz
• Bitrate: 64kbps - 128kbps
• Channels: Mono (1 channel)
• Maximum duration: No hard limit, but shorter is better for voice notes
• Maximum size: 16MB

Supported Audio Formats

• MP3 (audio/mpeg)
• OGG with Opus codec (audio/ogg)
• M4A/AAC (audio/mp4, audio/aac)
• WAV (audio/wav) - will be converted

Audio files sent via this endpoint will appear as voice messages (PTT) in WhatsApp, displayed with a play button and waveform. To send regular audio files as documents, use the Send Media endpoint with mediatype: "audio".

PTT vs Regular Audio

Voice Message (PTT) - This Endpoint

• Appears as a voice message with waveform
• Plays automatically in sequence
• Designed for quick voice communication
• Maximum 16MB file size

Regular Audio File - Send Media Endpoint

• Appears as an audio file attachment
• Requires manual play
• Suitable for music, podcasts, etc.
• Can be larger files

Error Responses

status · number

HTTP status code

message · string

Error description

Common Errors

Status Code	Error Message	Solution
400	”Owned media must be a url, base64, or valid file with buffer”	Ensure audio is provided as URL, base64, or file upload
401	Unauthorized	Check your API key
404	Not Found	Verify instance exists and is connected
500	Internal Server Error	Check audio file format and size

The audio URL must be publicly accessible. If you’re getting errors, verify that the URL can be accessed without authentication.