POST
/
audio_speed_changer
Python
import requests

url = "https://api.musicgpt.com/api/public/v1/audio_speed_changer"
headers = {"Authorization": "<API_KEY>"}

# Option 1: Use audio URL
payload = {
    "audio_url": "https://example.com/input_audio.mp3",
    "speed_change_factor": 1.5,
    "output_extension": "mp3"
}
response = requests.post(url, headers=headers, data=payload)
print(response.json())

# Option 2: Upload local audio file
payload = {
    "speed_change_factor": 1.25,
    "output_extension": "wav"
}
with open("input_audio.mp3", "rb") as f:
    files = {"audio_file": f}
    response = requests.post(url, headers=headers, data=payload, files=files)
print(response.json())
{
  "success": true,
  "conversion_id": "conv999",
  "credit_estimate": 45,
  "conversion_path": "https://example.com/output/converted_audio.mp3",
  "message": "Speed change task queued successfully"
}
Change the speed of your audio files without affecting quality. Audio Speed Changer allows you to easily speed up or slow down any audio file — perfect for creating remixes, practicing music, or adjusting spoken content.
  • ⏩ Speed up or slow down audio effortlessly
  • 🎶 Supports multiple formats like MP3, WAV, FLAC, and more
  • 🚀 Fast processing with high-quality output

​
Endpoint

POST /audio_speed_changer
Use this endpoint to adjust the speed of an audio file.

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Sample Output

Listen to the speed-changed audio:

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Try it Yourself

Visit the Audio Speed Changer Endpoint Explorer to upload audio files and adjust their playback speed.
⏩ Try different speed factors like 1.5x or 0.75x to test quality!

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Request Parameters

ParameterTypeRequiredDescription
audio_pathStringYesThe S3 path of the input audio file
conversion_idStringYesUnique identifier for this conversion request
speed_change_factorNumberYesFactor to change speed (e.g., 2.0 = double speed, 0.5 = half speed) (min: 0.25, max: 4.0)
output_extensionStringYesDesired output format (mp3, wav, flac, ogg, aac, webm)
webhook_urlStringOptionalURL to receive callback notification when processing completes
user_idStringOptionalUser ID for tracking (from authentication token)

​
Sample Request

​
Python

import requests

url = "https://api.musicgpt.com/api/public/v1/audio_speed_changer"
headers = {"Authorization": "<API_KEY>"}

# Option 1: Use audio URL
payload = {
    "audio_url": "https://example.com/input_audio.mp3",
    "speed_change_factor": 1.5,
    "output_extension": "mp3"
}
response = requests.post(url, headers=headers, data=payload)
print(response.json())

# Option 2: Upload local audio file
payload = {
    "speed_change_factor": 1.25,
    "output_extension": "wav"
}
with open("input_audio.mp3", "rb") as f:
    files = {"audio_file": f}
    response = requests.post(url, headers=headers, data=payload, files=files)
print(response.json())

​
Sample Response

​
Success (200 OK)

{
  "success":true,
  "task_id":"b0ac9d46-64d7-4843-af48-a0b6effe3666",
  "conversion_id":"fe19945b-d466-4183-b559-5d264bddd492",
  "eta":66,
  "credit_estimate":25.0,
  "message":"Message published to queue",
  "status":"IN_QUEUE"
}

​
Webhook Response

When transcription completes, your webhook will receive: 
{
  "success": true, 
  "conversion_type": "Audio Speed Changer", 
  "task_id": "b0ac9d46-64d7-4843-af48-a0b6effe3666", 
  "conversion_id": "fe19945b-d466-4183-b559-5d264bddd492", 
  "output_file": "https://lalals.s3.amazonaws.com/FileConversions/b0ac9d46-64d7-4843-af48-a0b6effe3666.wav", 
  "message": "Audio speed changer completed"
}
📂 The conversion_path field contains the direct link to download the speed-modified audio.

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Payload and Request Formation

Authorizations

​
Authorization
string
header
required

Body

multipart/form-data
​
audio_url
string
required

URL of the input audio to change speed.

Example:

"https://example.com/input_audio.mp3"

​
speed_change_factor
number
required

Factor to change the audio speed (min: 0.25, max: 4.0)

Required range: 0.25 <= x <= 4
Example:

1.5

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audio_path
string

Deprecated: use audio_url instead.

Example:

"https://example.com/input_audio.mp3"

​
audio_file
file

Audio file to upload and process directly.

​
output_extension
enum<string>

Desired output format.

Available options:
mp3,
wav,
flac,
ogg,
aac,
webm
Example:

"mp3"

​
webhook_url
string

Callback URL for async processing results.

Example:

"http://your-webhook-url.com/callback"

Response

Successfully initiated audio speed change

​
success
boolean
​
conversion_id
string
​
credit_estimate
number
​
conversion_path
string
​
message
string