# Audio Time Stretch & Pitch

Change speed without pitch, or pitch without speed

> Canonical page: https://elysiatools.com/en/tools/audio-time-stretch-pitch

- **Category:** Media

- **Keywords:** audio, time stretch, pitch shift, tempo, ffmpeg

## Overview

Uses FFmpeg atempo for time-stretching and asetrate+atempo for pitch shifting.

## Inputs

- **Audio File** (file): Select an audio file
- **Mode** (select)
- **Tempo Factor** (number): 1.0
- **Pitch Shift (semitones)** (number): 0
- **Output Format** (select)

## When to use

- When you need to speed up or slow down audio for efficient listening or editing without pitch distortion.
- When transposing music to a different key for practice, performance, or compatibility.
- When creating audio effects that require independent speed and pitch adjustments, such as for video synchronization.

## How it works

- Upload your audio file in a supported format like MP3, WAV, or AAC.
- Select the operation mode: time-stretch to change speed or pitch-shift to change pitch.
- Set the tempo factor (0.25 to 4) or semitone shift (-12 to 12) as needed.
- Choose the output format and download the processed file.

## Use cases

- Adjusting podcast or audiobook playback speed for time-efficient listening without voice distortion.
- Transposing musical tracks to match vocal or instrumental ranges during practice or recording.
- Synchronizing audio with slow-motion or fast-forward video sequences while maintaining clarity.

## Frequently asked questions

### What audio formats can I upload?

Any audio format supported by FFmpeg, such as MP3, WAV, AAC, OGG, FLAC, and more.

### How does time-stretching preserve pitch?

It uses FFmpeg's atempo filter to adjust speed while keeping the original pitch unchanged.

### Can I process multiple files at once?

No, the tool handles one audio file per session to maintain processing quality.

### What is the maximum file size allowed?

Audio files must be under 200 MB.

### Is there a limit on tempo or pitch adjustment?

Tempo factor ranges from 0.25 to 4, and pitch shift from -12 to 12 semitones.

## Related tools

- [Audio Key Change for Singers](https://elysiatools.com/en/tools/audio-key-change-for-singers): Transpose a song by key or semitones while preserving its duration and speed.
- [Audio Pitch Down](https://elysiatools.com/en/tools/audio-pitch-down): Decrease pitch without changing speed
- [Audio Pitch Up](https://elysiatools.com/en/tools/audio-pitch-up): Increase pitch without changing speed
- [Audio Resample Speed](https://elysiatools.com/en/tools/audio-resample-speed): Change speed by resampling (pitch shifts with speed)
- [Audio Set Pitch](https://elysiatools.com/en/tools/audio-set-pitch): Set pitch up or down without changing speed
- [Audio Set Speed](https://elysiatools.com/en/tools/audio-set-speed): Set audio playback speed without changing pitch
- [Audio Slow Down](https://elysiatools.com/en/tools/audio-slow-down): Slow down audio playback without changing pitch
- [Audio Speed Changer](https://elysiatools.com/en/tools/audio-speed-changer): Change audio playback speed while maintaining original pitch using time-stretching algorithms

## Samples

- [Copyright-Free FLAC Audio Samples](https://elysiatools.com/en/samples/flac-samples): Lossless FLAC audio samples for testing and development, mirrored from MP3 set with nature sounds and meditation music
- [Copyright-Free MP3 Audio Samples](https://elysiatools.com/en/samples/mp3-samples): Collection of royalty-free audio samples for testing and development purposes including nature sounds, meditation music, and ambient audio
- [Copyright-Free WAV Audio Samples](https://elysiatools.com/en/samples/wav-samples): Uncompressed PCM WAV audio samples for testing and development, mirrored from MP3 set with nature sounds and meditation music
- [Copyright-Free Raw PCM Audio Samples](https://elysiatools.com/en/samples/pcm-samples): Raw PCM s16le audio samples featuring nature ambience and relaxing music for waveform, playback, and conversion workflows

## Related content

- [Audio Pitch, Tempo, Looping, and Reverse Playback Tools](https://elysiatools.com/en/hubs/audio-pitch-tempo-remix-workflows): Shape pitch, tempo, speed, beat alignment, loops, reverse playback, and stutter patterns into a controlled audio remix workflow.