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POST
/
v1
/
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"
}

Documentation Index

Fetch the complete documentation index at: https://docs.musicgpt.com/llms.txt

Use this file to discover all available pages before exploring further.

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

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Endpoint

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

​
Sample Output

Listen to the speed-changed audio:

​
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!

​
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)
content-type: multipart/form-data

​
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.

​
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

​
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<float>
​
conversion_path
string
​
message
string