Change Audio Speed
Free online audio speed changer. Speed up or slow down audio without changing pitch. No download required, process locally for privacy. Perfect for lecture recordings, podcast listening.
The audio speed adjustment tool changes audio playback speed, accelerating or decelerating playback rhythm. Speed adjustment range supports 0.5x to 2x, allowing flexible selection based on your needs. Whether speeding up lengthy podcasts to save time, or slowing down speech rate for language learning and shadowing, simple multiplier settings handle it all with one click.
This tool provides two speed adjustment modes: speed change without pitch shift and speed change with pitch shift. Speed change without pitch shift maintains original pitch while changing playback speed, suitable for podcast acceleration and language learning. Speed change with pitch shift changes pitch along with speed, suitable for creating fun sound effects and special effects. Typical applications include 1.5x speed podcast listening, 0.75x speed language learning shadowing, and slow-speed audio detail analysis.
All audio file processing is performed entirely in your browser locally—files are never uploaded to any server. This means your private recordings, music files, and commercial audio materials remain on your device throughout the entire speed adjustment process, maximizing privacy and data security.
How to Adjust Audio Speed
Upload Audio File
Click the upload area or drag and drop audio files. Supports mainstream formats including MP3, WAV, FLAC, and AAC. You can select multiple files at once.
Select Speed Multiplier
Choose a speed multiplier from 0.5x to 2x range. 0.5x is half speed, 1.5x is fast, 2x is very fast—select flexibly based on your needs.
Choose Pitch Preservation
Select speed change without pitch shift (maintain original pitch) or speed change with pitch shift (pitch changes with speed). Podcasts and language learning recommend maintaining pitch.
Download Processed Audio
After processing completes, audio files are automatically downloaded to your device. For batch processing, you can download individually for easy management of multiple output files.
Core Features
Speed Range 0.5x-2x
Supports speed range from 0.5x to 2x, covering slow, normal, fast, and very fast playback speeds. Flexibly choose appropriate multiplier based on different needs like listening, learning, and analysis.
Pitch Preservation
Speed change without pitch shift mode maintains original pitch while changing playback speed, avoiding voice becoming sharp or deep. Suitable for podcast accelerated listening and language learning shadowing, maintaining natural listening experience.
Pitch Changes with Speed
Speed change with pitch shift mode causes pitch to rise or fall along with playback speed changes. Suitable for creating fun sound effects, special effects, and creative audio, providing more possibilities for content creation.
Batch Processing
Upload multiple audio files at once and batch process them with unified speed adjustment settings. No need to process files individually—greatly improving efficiency for handling large audio collections.
| Speed Multiplier | Effect | Typical Use |
|---|---|---|
| 0.5x | Half speed | Language learning |
| 0.75x | Slightly slow | Careful listening |
| 1.0x | Normal speed | Original playback |
| 1.25x | Slightly fast | Efficient listening |
| 1.5x | Fast | Podcast acceleration |
| 2.0x | Very fast | Quick browsing |
Use Cases
Podcast Acceleration
Listen to podcasts at 1.5x speed to save time while maintaining content intelligibility. Suitable for fragmented scenarios like commuting and exercise, allowing you to acquire more information in limited time.
Language Learning
Shadow foreign language audio at 0.75x speed to clearly hear every pronunciation detail. Maintaining pitch keeps speech rate slow but voice natural—an effective aid for language learning and oral training.
Audio Analysis
Analyze audio details at slow speed, such as instrument playing, vocal articulation, and ambient sound effects. Slow playback makes subtle details easier to identify, suitable for music research and audio quality assessment.
FAQ
Will pitch change after speed adjustment?
This depends on the speed adjustment mode you choose. In speed change with pitch shift mode, pitch rises or falls along with playback speed changes—speeding up makes voice sharp, slowing down makes voice deep. In speed change without pitch shift mode, pitch maintains original state unchanged, only playback speed changes. Podcast acceleration and language learning recommend using speed change without pitch shift mode to maintain natural listening experience.
Can I keep pitch unchanged?
Yes. This tool provides speed change without pitch shift mode that maintains original pitch unchanged while changing playback speed. This mode is achieved through specialized audio processing algorithms, avoiding voice becoming sharp or deep problems, suitable for scenarios requiring natural listening experience like podcast accelerated listening and language learning shadowing. Select the preserve pitch option during operation to enable this mode.
What is the speed adjustment range?
This tool supports 0.5x to 2x speed adjustment range. 0.5x is half speed, suitable for language learning and detail analysis; 0.75x is slightly slow, suitable for careful listening; 1.0x is normal speed; 1.25x is slightly fast, suitable for efficient listening; 1.5x is fast, suitable for podcast acceleration; 2.0x is very fast, suitable for quick content browsing. You can flexibly choose appropriate multiplier based on actual needs.
Can I process multiple files at once?
Yes. This tool supports batch processing. You can upload multiple audio files at once and batch process them with unified speed multiplier and pitch mode settings. All files are speed-adjusted locally in your browser sequentially, eliminating the need for individual processing and significantly saving time. The number of files for batch processing is only limited by your device's available memory, suitable for handling large audio collections.
Will quality decrease after speed adjustment?
Speed adjustment itself does not significantly reduce quality—the tool adjusts playback speed through resampling algorithms. Speed change without pitch shift mode may produce slight artifacts at extreme multipliers due to additional pitch preservation processing. If output format is the same as source file, quality is basically identical to original; choosing to convert to other formats means final quality depends on target format encoding characteristics.
What audio formats are supported?
This tool supports speed adjustment processing for mainstream audio formats including MP3, WAV, FLAC, AAC, OGG, and M4A. These formats cover most everyday use and professional production scenarios. Processed audio defaults to maintaining source file format, and you can also choose to output as other formats based on needs, flexibly adapting to different playback devices and purposes.