Why change the speed of audio?
Slowing a song down helps you work out a guitar solo note by note, learn a dance routine or catch a phrase in another language. Speeding it up lets you get through a podcast or lecture in less time, or fit a voiceover into the length an ad requires.
The tool gives you two ways to do it. With “Keep pitch” on, only the tempo changes: voices won’t turn squeaky like a chipmunk or deep like a robot, because the audio is stretched or squeezed in small overlapping chunks that are lined up with each other (the WSOLA method many podcast players use). With it off, speed and pitch change together, just like spinning a record or tape faster or slower.
You can choose any value from 0.25× to 3×, or use the quick buttons for 0.5×, 0.75×, 1.25×, 1.5× and 2×. The further you move from 1×, the more noticeable the processing becomes, especially on music with lots of reverb; for spoken word, changes up to 1.5× sound very natural.
The audio is processed in your browser and never uploaded to a server. You get one free try with a single file; with ToolStudio Pro you get unlimited use and can change the speed of several files at once.
How to change the speed of audio
- Upload your audio file by dragging it in or clicking.
- Pick the speed with the slider or one of the quick buttons.
- Decide whether to keep the original pitch or change it along with the speed.
- Choose the output format (MP3 or WAV) and click “Change speed”.
- Listen to the result and download it.
When to change the speed
- Slow down a song to learn it on an instrument.
- Speed up lectures, audiobooks or podcasts to get through them faster.
- Fit a voiceover to the length of an ad or video.
- Slow down audio in another language to transcribe or understand it better.
- Practice a dance routine at a slower tempo and build up gradually.
Supported formats
- Input: MP3, WAV, M4A, AAC, OGG, OPUS, FLAC, WEBM, AIFF and the audio from MP4 or MOV videos.
- Output: MP3 at 128, 192, 256 or 320 kbps, or 16-bit PCM WAV.
- Up to 250 MB per file. The sample rate and channels (mono or stereo) are preserved.
Frequently Asked Questions
Can I change the speed without changing the pitch?
Yes, that’s the default. With “Keep pitch” on, only the tempo changes; turn it off if you want the sped-up or slowed-down record effect.
What are the minimum and maximum speeds?
From 0.25× (four times slower) to 3× (three times faster). If you want to change the pitch on purpose too, try the Nightcore or Slowed + Reverb tools.
Which formats are supported?
You can open MP3, WAV, M4A, AAC, OGG, OPUS, FLAC, WEBM and the audio track of an MP4 or MOV video (exact support depends on your browser). The result downloads as MP3 at 128 to 320 kbps or as uncompressed WAV.
Is my audio uploaded to a server?
No. Your audio is read, processed and converted right in your browser using the Web Audio API. The file is never uploaded to a server and never leaves your device.
Is it free?
You get one free try per tool: one audio file. You can reprocess that same file with different settings as many times as you like, but to process a new file you need ToolStudio Pro, which gives you unlimited use of every tool, batch processing (several files at once, downloaded together in a ZIP) and no ads. You can cancel anytime.
