Slowed and Reverb Generator
Make a slowed and reverb version of any song, or speed it up for nightcore. Set the speed, reverb, bass boost and an optional 8D pan, hear the result live, then download a WAV or MP3. Your song stays on your device.
- 1Open a song
- 2Pick a sound
- 3Download
1Open a song
or drop a file here · MP3, WAV, M4A, OGG, FLAC, or a video’s sound
The preview plays with your settings as you change them. The time shown is the new, slowed or sped-up time.
Your song never leaves your device. It’s processed in your browser. We count visits and finished downloads (tool name only) with analytics that sets no cookies.
2Pick a sound
3Download
MP3 is encoded on your device. The encoder is a one-time download of about 32 MB.
How to make a slowed and reverb song
- Open your song. Press Choose a song, or drop an audio or video file on the box. Video files work too: the tool takes their sound.
- Pick Slowed + reverb. It starts at 0.85× speed with a 3-second reverb and a little bass. Press Play preview and move the sliders until it sounds right; the preview follows every change.
- Choose a format. WAV 16-bit plays everywhere. MP3 is smaller and is encoded on your device.
- Create and download. Press Create file, then Download. The file is made from the full song at its own sample rate.
Nightcore maker
Nightcore is the opposite: the song is sped up, so it is shorter and every note is higher. Press Nightcore to start at 1.25× speed, about 3.9 semitones higher, with no reverb. Go up to 1.5× for an even faster, higher version, or add a touch of reverb.
What each control does
- Speed plays the song faster or slower, like a record or tape. Pitch moves with it: 0.85× is about 2.8 semitones lower, 0.8× about 3.9 lower, 1.25× about 3.9 higher. The note under the slider shows the exact figure and the new length.
- Reverb amount blends the dry song with a reverb copy. 0% is no reverb at all.
- Reverb length is how long the reverb takes to fade to one-thousandth of its level (60 dB down): short sounds like a small room, long like a hall.
- Bass boost raises the low end below about 120 Hz by up to 12 dB.
- 8D pan moves the sound slowly between your left and right ear. It is a left-right sweep, not 3D surround, and it works best with headphones.
What you get
- A stereo file at your song’s own sample rate (an MP3 of a song above 48,000 Hz is made at 48,000 or 44,100 Hz).
- The exact new length. A 3:00 song at 0.85× becomes 3:31.76, plus the reverb tail if you let it ring out.
- No clipping. Bass and reverb can push the sound past full scale. If they do, the whole file is turned down until its loudest peak is 1 dB below full scale, and the download panel says by how much. Otherwise the level is left alone.
- Built with the Web Audio API that your browser already has (W3C specification, read 27 October 2026): the speed change, reverb, bass filter and pan all run on your device.
FAQ
How do I make a song slowed and reverb?
Open the song here, keep the Slowed + reverb preset, press Play preview to check it, then press Create file and Download. If it is too slow or too wet, move Speed or Reverb amount while it plays.
How do I make a nightcore song?
Open the song and press Nightcore. It plays at 1.25× speed, so it is higher and shorter. Raise Speed for more, then create and download the file.
Can I slow it down without changing the pitch?
Not with this tool. Speed and pitch move together here, the way a record or tape sounds when it is played slower or faster. That lower, heavier pitch is part of the slowed and reverb sound.
Can I download an MP3?
Yes. Choose MP3 320 kbps or 192 kbps under Format. The MP3 is encoded on your device with the LAME encoder, which the page downloads once (about 32 MB) the first time you ask for an MP3. WAV needs no extra download.
What is 8D audio?
Usually a song with a lot of reverb whose sound slowly circles between your ears. Here the 8D pan sweeps the sound from left to right and back; set how long one sweep takes. Listen with headphones.
Why is my file quieter than the original?
Only when the bass boost or reverb would have clipped (gone past full scale and crackled). The tool then turns the whole file down until its loudest peak is 1 dB below full scale, and shows by how much under Download. Lower Bass boost or Reverb amount to keep more level.
Does this tool upload my song?
No. The song is opened, changed and saved by your browser on your own device and is never sent to a server. You can check: open your browser’s developer tools, go to the Network tab, and make a file. The page counts visits and finished downloads (tool name only) with analytics that sets no cookies, and no audio is ever sent (see privacy).
Is there a length limit?
No fixed limit; your device’s memory is the limit. The whole song is held in memory while the file is made, so songs over 15 minutes get a warning first. A normal 3 to 5 minute song works on phones and computers.