Speed Up or Slow Down Audio
Drop in an MP3, a voice message or a song, set the speed anywhere from 0.25× to 3× and hear the result right away. Voices keep their normal pitch, or change like a record if that's the effect you want.
- 0.25× to 3×
- Natural-sounding voice
- Live preview
- 100% private
100% private — Everything is processed directly in your browser: your files, voice, and image are never sent to Chatzam's servers.
How do you speed up an audio file?
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Add your file
Drag in your MP3, M4A, WAV, voice memo or even a video: the waveform appears within seconds.
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Set the speed
Move the slider or tap 1.25×, 1.5× or 2×, then press ▶ to hear the effect live.
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Download
Pick the format (same as the original, MP3, WAV, M4A, FLAC or M4R) and download the new file.
Change the tempo without any software
No chipmunk voice
By default the pitch is kept: a sped-up voice still sounds natural, and a slowed-down song stays in the same key.
Or a vinyl effect
Untick the option and the pitch follows the speed, like a record played too fast or too slow: perfect for "sped up" and "slowed" versions.
Listen before you save
The preview applies the speed live while it plays, so you find the right setting before the file is created.
Your files stay with you
Everything is processed in your browser: your recordings are never sent to a server.
Speed up a voice memo, a lecture or a podcast
Listening to a long voice message, a recorded lecture or an audiobook at 1.25× or 1.5× saves a lot of time without hurting comprehension. With the pitch preserved, the voice still sounds natural: only the pace changes. A one-hour recording played at 1.5× lasts just 40 minutes, and the new length is shown under the slider before you even export. The other way round, slowing down to 0.75× or 0.5× helps you transcribe a fast passage, learn the lyrics of a song or follow a foreign language.
Slow down a song to learn it or practice
Musicians and dancers often slow a track down to work out a solo, a routine or a tricky passage. With the pitch kept, the song stays in the same key, so you can play along on an instrument tuned as usual. Start at 0.75×, then gradually work back up to full speed. If you also want to transpose the song, use the Pitch Changer tool.
"Sped up" and "slowed" songs: speed and pitch together
The "sped up" versions that go viral on TikTok are faster with a higher voice, and "slowed" versions are slower with a deeper one. To get that sound, untick "Keep the same pitch": speed and pitch then change together, exactly like a record. Around 1.25× works well for a sped up version, and around 0.8× for a slowed one. The preview lets you hear the result instantly.
Which formats, and what about quality?
The tool reads MP3, WAV, M4A, FLAC, OGG, Opus, AAC, WMA and AMR files, as well as the sound of MP4, MOV, MKV or WEBM videos. The new file can be saved in the original format (OGG for an Opus source), or as MP3, WAV, M4A, FLAC or M4R (iPhone ringtone). Because the sound is recalculated, it is re-encoded: choose WAV or FLAC to avoid any further quality loss, or MP3 or M4A for a small file. To speed up a video and keep the picture, use Change Video Speed instead.
Frequently Asked Questions
How do I speed up audio without the voice getting high-pitched?
Leave "Keep the same pitch" ticked. The speed changes but the voice keeps its normal tone. Listen to the preview to check before downloading.
How do I slow down a song?
Add the track and move the slider below 1×, for example to 0.75× or 0.5×. Keep the pitch to stay in the same key, or untick the option for a deeper "slowed" effect.
How fast or slow can it go?
From 0.25× (four times slower) to 3× (three times faster), in steps of 0.05. Above 2×, speech gets hard to follow, even with the pitch preserved.
Can I speed up the sound of a video?
Yes: drop in the video and the tool keeps only its soundtrack, saved as an audio file. To change the speed of the whole video, picture included, use Change Video Speed.
Does it reduce the quality?
Changing the speed recalculates the sound, so the file is re-encoded. As MP3 or M4A the loss is slight and rarely audible; as WAV or FLAC no extra compression loss is added.
Is my file uploaded to a server?
No. Everything happens in your browser with FFmpeg: the file never leaves your device. It's free and no sign-up is needed.