Original audio
Conversion settings
How to change audio or music speed
- Choose an audio or MP4 fileDrag and drop an MP3, WAV, M4A, MP4, or another supported file, or click to select one. Files up to 500 MB are supported.
- Set the speed or BPMChoose a playback speed from 0.1x to 5x, or enter the original and target BPM.
- Check how it soundsLeave Preserve pitch enabled if you want to change speed without changing the song's key. Preview the audio and check the estimated duration.
- Convert and saveChoose MP3 192 kbps, MP3 320 kbps, or 16-bit WAV, then convert and download the finished audio.
This free online Audio Speed Changer requires no registration. Loading, previewing, processing, and exporting all happen on your device. Your MP3 or other selected file is not uploaded to Benri Lab.
Change and save the playback speed of MP3, WAV, and M4A files
Load an MP3, WAV, M4A, or another supported audio file and change its playback speed from 0.1x to 5x. Save the adjusted result as an MP3 or WAV file.
Presets cover slow playback at 0.5x and 0.75x as well as faster playback at 1.5x and 2x. To save an MP3 at 1.5x or 2x speed, simply choose the preset and convert it.
Slow down or speed up a song without changing pitch
With Preserve pitch enabled, you can change the song's speed while keeping the pitch as close to the original as possible. This works well for slow practice, faster listening, and general music speed adjustment.
Slowing a song without changing its key helps with transcription and instrument practice. Speeding up spoken audio while preserving pitch also avoids the exaggerated high-pitched “chipmunk” effect.
Change BPM and match a song's tempo
To use the tool as a BPM changer, detect or enter the original BPM, then set a target BPM. For
example, changing a 120 BPM song to 128 BPM calculates the required speed as
128 ÷ 120 = 1.0667x.
You can use this for changing a song's tempo, matching tracks, or preparing music for dance practice. Leave Preserve pitch enabled to keep the song's key as close to the original as possible. BPM detection is an estimate, so adjust it manually or use the ÷2 and ×2 controls when needed.
Slow down songs for transcription, instruments, and dance practice
Try 0.5x for detailed guitar or bass transcription, or 0.75x for piano and dance practice. Enable pitch preservation when you want to practice in the original key. Drummers can enter a BPM and gradually increase the target tempo as they improve.
Slow down language audio or speed up meetings and lectures
Slowing language-learning audio makes difficult pronunciation easier to hear. Set an MP3 to 0.5x or 0.75x and preserve pitch for clearer, more natural-sounding slow playback.
For meetings, lectures, podcasts, and long recordings, 1.5x or 2x playback saves time. Exporting the faster audio lets you listen at the same speed in players that do not offer speed controls.
Choosing a playback speed
| Speed | Common uses |
|---|---|
| 0.1x | Inspecting a very short section in detail; audio quality is strongly affected |
| 0.5x | Transcription and close listening to pronunciation |
| 0.75x | Language learning, instrument practice, and dance rehearsal |
| 1.0x | Original speed; no speed change |
| 1.25x | Slightly faster meetings, lectures, and podcasts |
| 1.5x | A practical balance between clarity and time savings |
| 2.0x | Quick review of familiar lectures or meeting audio |
| 5.0x | Scanning a short audio clip; audio quality is strongly affected |
Speed, tempo, and pitch: what's the difference?
Speed controls the overall duration of the audio, tempo is the musical pulse measured in BPM, and pitch is how high or low a voice or note sounds. With Preserve pitch enabled, the duration changes while pitch stays as close to the original as possible. When disabled, speed and pitch change together like fast or slow tape.
In pitch mode, +12 semitones is about 2x speed and -12 semitones is about 0.5x speed. To change only the key while keeping the duration nearly the same, use our Pitch Changer.
Frequently asked questions
Can I change pitch without changing speed?
Pitch mode in this tool changes pitch and speed together. To change only the key while keeping the duration nearly the same, use our 🔗 Pitch Changer.
Can I change the playback speed of audio, music, or MP3 files?
Yes. Load an MP3 or another supported audio file and change its speed from 0.1x to 5x. You can export MP3 at 192 or 320 kbps, or 16-bit WAV.
Can I change music or MP3 speed without changing pitch?
Yes. Keep Preserve pitch enabled to speed up or slow down a song while keeping its pitch as close to the original as possible.
Can I save an MP3 at 1.5x or 2x speed?
Yes. Choose the 1.5x or 2x preset, then export the result as MP3 or WAV. This is useful for reviewing lectures, meetings, and podcasts in less time.
Does it support WAV and M4A speed changes?
Yes. It supports common formats your browser can decode, including WAV, M4A, MP3, AAC, OGG, FLAC, AIFF, and audio from MP4 files. Output is MP3 or WAV.
Can I slow a song to 0.5x or 0.75x for transcription or practice?
Yes. Slower playback makes notes and timing easier to follow for guitar, piano, bass, dance, and other practice. Enable pitch preservation to stay close to the original key.
Can I slow down language-learning audio?
Yes. Set listening audio to 0.5x or 0.75x and preserve pitch to review pronunciation and difficult sections more clearly.
Can I change a 120 BPM song to 128 BPM?
Yes. Enter 120 as the original BPM and 128 as the target BPM. The tool calculates a speed of about 1.0667x. Enable pitch preservation to stay close to the original key.
Is this tool free, and are my files uploaded?
It is free and requires no registration. Processing happens in your browser, and the selected file is not uploaded to Benri Lab's servers.
Does it work on iPhone and Android?
It works in major browsers. Long audio and extreme slowdowns use substantial memory, so a short file or desktop browser is recommended. On iPhone, the finished audio may open in a new tab when saved.
Does changing speed affect audio quality?
Pitch-preserving processing and MP3 re-encoding can affect audio quality. For fewer changes, use a speed close to 1.0x and export as WAV.
Can I paste a YouTube URL?
No. This tool does not load URLs. Please use a local audio file you own or have permission to use.
See the Open Source Licenses page for information about the libraries used by this tool.