> ## 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.
# Audio Speed Changer
> Processes an audio file to change its playback speed based on a speed factor.
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
```http theme={null}
POST /v1/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](/api-documentation/endpoint/audio_speed_changer) to upload audio files and adjust their playback speed.
> ⏩ Try different speed factors like 1.5x or 0.75x to test quality!
***
## Request Parameters
| Parameter | Type | Required | Description |
| - | - | - | - |
| `audio_file` | `File` | Optional | Upload the audio file directly. Required if `audio_url` is not provided. |
| `audio_url` | `String` | Optional | URL to the audio file. |
| `speed_change_factor` | Number | Yes | Factor to change speed (e.g., 2.0 = double speed, 0.5 = half speed) (min: 0.25, max: 4.0) |
| `output_extension` | String | Yes | Desired output format (`mp3`, `wav`, `flac`, `ogg`, `aac`, `webm`) |
| `webhook_url` | String | Optional | URL to receive callback notification when processing completes |
> **Max input audio length:** 8 minutes. See [Audio Length Limits](/api-documentation/utilities/ratelimits#audio-length-limits).
> **Note:** Either audio\_file or audio\_url must be provided.
> **content-type:** multipart/form-data
***
## Sample Request
### Python
```python theme={null}
import requests
url = "https://api.musicgpt.com/api/public/v1/audio_speed_changer"
headers = {"Authorization": ""}
payload = {
"speed_change_factor": 1.5,
"output_extension": "mp3"
}
# Option 1: audio_url
payload["audio_url"] = ""
response = requests.post(url, headers=headers, data=payload)
# Option 2: File Upload
# 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)
```json theme={null}
{
"success":true,
"task_id":"b0ac9d46-64d7-4843-af48-a0b6effe3666",
"conversion_id":"fe19945b-d466-4183-b559-5d264bddd492",
"eta":66,
"credit_estimate":0.15,
"message":"Message published to queue",
"status":"IN_QUEUE"
}
```
***
## Webhook Response
When transcription completes, your webhook will receive:
```json theme={null}
{
"success": true,
"conversion_type": "Audio Speed Changer",
"task_id": "b0ac9d46-64d7-4843-af48-a0b6effe3666",
"conversion_id": "fe19945b-d466-4183-b559-5d264bddd492",
"output_file": "https://cdn1.musicgpt.com/conversions/e477a121-ba71-4753-96ae-874779f0623a/e477a121-ba71-4753-96ae-874779f0623a.mp3",
"message": "Audio speed changer completed",
"title": "Audio Speed Changer"
}
```
***
## Payload and Request Formation
## OpenAPI
````yaml POST /v1/audio_speed_changer
openapi: 3.1.0
info:
title: Musicgpt API
version: 1.0.0
description: API for retrieving conversion details by ID.
servers:
- url: https://api.musicgpt.com/api/public
description: Production server
security: []
paths:
/v1/audio_speed_changer:
post:
summary: Change the speed of an audio file
description: >-
Processes an audio file to change its playback speed based on a speed
factor.
requestBody:
required: true
content:
multipart/form-data:
schema:
type: object
properties:
audio_url:
type: string
description: 'Input audio URL (supported format: YouTube URL).'
audio_file:
type: string
format: binary
description: Audio file to upload and process directly.
speed_change_factor:
type: number
description: 'Factor to change the audio speed (min: 0.25, max: 4.0)'
minimum: 0.25
maximum: 4
example: 1.5
output_extension:
type: string
enum:
- mp3
- wav
- flac
- ogg
- aac
- webm
description: Desired output format.
example: mp3
webhook_url:
type: string
description: Callback URL for async processing results.
example: http://your-webhook-url.com/callback
required:
- speed_change_factor
anyOf:
- required:
- audio_url
- required:
- audio_file
responses:
'200':
description: Successfully initiated task
content:
application/json:
schema:
type: object
properties:
success:
type: boolean
task_id:
type: string
conversion_id:
type: string
eta:
type: integer
credit_estimate:
type: number
message:
type: string
status:
type: string
example:
success: true
task_id: b0ac9d46-64d7-4843-af48-a0b6effe3666
conversion_id: fe19945b-d466-4183-b559-5d264bddd492
eta: 66
credit_estimate: 0.15
message: Message published to queue
status: IN_QUEUE
'402':
description: Payment Required
content:
application/json:
schema:
type: object
properties:
success:
type: boolean
error_code:
type: string
message:
type: string
example:
success: false
error_code: INSUFFICIENT_CREDITS
message: ''
'422':
description: Unprocessable Entity
content:
application/json:
schema:
type: object
properties:
success:
type: boolean
error_code:
type: string
message:
type: string
example:
success: false
error_code: UNPROCESSABLE_CONTENT
message: ''
'500':
description: Internal Server Error
content:
application/json:
schema:
type: object
properties:
success:
type: boolean
error_code:
type: string
message:
type: string
example:
success: false
error_code: INTERNAL_SERVER_ERROR
message: ''
security:
- ApiKeyAuth: []
x-codeSamples:
- lang: Python
source: >-
import requests
url = "https://api.musicgpt.com/api/public/v1/audio_speed_changer"
headers = {"Authorization": ""}
payload = {
"speed_change_factor": 1.5,
"output_extension": "mp3"
}
# Option 1: audio_url
payload["audio_url"] = ""
response = requests.post(url, headers=headers, data=payload)
# Option 2: File Upload
# 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())
components:
securitySchemes:
ApiKeyAuth:
type: apiKey
in: header
name: Authorization
````
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