Choose an MP3, WAV, FLAC, or OGG file in the converter above.
Slowed Reverb Converter Online
MP3, WAV, FLAC & OGG — No App, No Signup
Convert any song into slowed and reverb audio directly in your browser. Upload a file, slow the speed, add reverb, preview the result, and export MP3 or WAV. Processing stays on your device.
Free online toolNo signupWorks in browserMP3, WAV, FLAC, OGG supportedPrivate client-side processing
Drop your song here or browse
WAV, MP3, FLAC, or OGG
0.85x
With the pitch shift folded in, the track is playing at 0.90x — speed and pitch drive the same playback rate, so they multiply.
42%
2.8s
+1 semitone
3 dB
Presets
Slowed + Reverb
0.90x playback, 42% reverb, 2.8s room, +1 semitone, 3 dB bass.
Daycore
0.67x playback, 60% reverb, 3.5s room, -2 semitones, 6 dB bass.
Nightcore
1.49x playback, 10% reverb, 1.0s room, +3 semitones, 0 dB bass.
Sped Up
1.20x playback, 0% reverb, 1.0s room, 0 semitones, 0 dB bass.
Preview Mode
How to Convert a Song to Slowed Reverb
Start with 0.82x to 0.88x speed, 35% to 45% reverb wet mix, and 2 to 4 seconds of decay.
Preview the chorus or loudest section, then reduce wet mix if vocals sound muddy.
Export MP3 for sharing or WAV if you plan to edit the result again.
Before You Convert
Do I need to install an app?
No. The converter runs in the browser on iPhone, Android, Windows, macOS, and Linux — there is no desktop installer and no mobile APK. That also means nothing to uninstall afterwards, which matters if you are converting one song rather than starting a hobby.
Should I convert from MP3 or from WAV?
Convert from the best source you have. Slowing a track stretches its artefacts along with everything else, so a low-bitrate MP3 that sounded acceptable at normal speed can reveal audible swirl at 0.85x. If you only have the MP3, it will still work — just expect the ceiling to be set by the source rather than by the tool.
Which export format should I pick?
MP3 if the file is going straight to a platform, WAV if it is going into another editor. The reason is re-encoding: exporting MP3 from an MP3 source means a second lossy pass, and if you then drop that into a video editor which encodes again, you are three generations deep. WAV avoids that entirely at the cost of a much larger file.
Is my audio uploaded to a server?
No. Decoding, processing, and export all happen in your browser using the Web Audio API, so the file never leaves your device. The practical consequence is that there is no server-side size limit to hit — the constraint is your own device's memory — and no copy of your track sitting in someone else's storage.
What Your Source File Costs You
Converting to slowed reverb is unusually unforgiving of a poor source, and the reason is worth understanding rather than just being told to use a good file. Lossy encoders like MP3 work by discarding detail the ear is unlikely to notice — but that judgement is made about the audio at its original speed. Slow the track down and every artefact stretches with it. A brief smear on a hi-hat that was masked at full tempo becomes a longer, more exposed sound at 0.85x, where nothing is moving fast enough to hide it any more.
Reverb then makes it worse, because reverb is the one effect that deliberately extends everything it touches. Artefacts you have already stretched get a tail attached to them. This is the real reason slowed edits from a bad rip sound cloudy rather than spacious.
| Source | Holds up | What you will hear |
|---|---|---|
| WAV / FLAC | Best | No coding artefacts to stretch. Whatever you hear afterwards came from the recording or from your settings, not from the file format. |
| MP3 320 kbps | Very good | Artefacts exist but sit far enough below the music that slowing rarely exposes them. Fine for almost every edit. |
| MP3 192 kbps | Usable | Cymbals and reverb tails are where you will notice it first — a faint watery shimmer that was inaudible at normal speed. |
| MP3 128 kbps | Audible | The classic swirl on hi-hats and vocal sibilance. Slowing to 0.85x makes it about 18% longer in real time, which is enough for the ear to lock onto it. |
| Audio ripped from video | Worst | Usually already lossy, often loudness-normalised by the platform, and sometimes re-encoded more than once. Reverb on top of that tends to sound cloudy rather than spacious. |
Counting Your Lossy Generations
Each pass through a lossy encoder throws away detail, and the losses accumulate — the second encoder cannot recover what the first discarded, and it makes its own cuts on top. Most people converting a song are further down this chain than they realise:
- The track was encoded when it was released or uploaded.
- It was re-encoded if you pulled it from a streaming or video platform.
- Exporting MP3 from this converter is another pass.
- Dropping that into a video editor and rendering makes a fourth, and posting it to a social platform usually makes a fifth.
You control steps three and four. Exporting WAV from here removes one generation entirely, and if the edit is heading into a video editor, handing it a WAV means the only lossy step left is the platform’s own. The file is far larger — roughly 10 MB per minute in stereo at 44.1 kHz, against about 2.4 MB for a 320 kbps MP3 — but that only matters if you are uploading the audio itself rather than a rendered video. Export MP3 when the file is the final artefact; export WAV when anything downstream is going to encode it again.
Best Starting Settings
For most songs, start with 0.85x speed, 38% wet mix, 2.8s decay, and +3 dB bass. Keep reverb under 40% on vocal-heavy tracks; for phonk or bass edits, use less reverb and more bass.
One thing worth knowing before you reach for the pitch control: speed and pitch drive the same playback rate on this tool, so they multiply rather than apply separately. Adding +1 semitone to a 0.85x setting does not leave you at 0.85x with a brighter vocal — it puts the track at 0.90x, outside the 0.80–0.88x range that gives slowed reverb its character. If a slowed edit sounds too dark, it is usually better to lift the speed a little than to correct it with pitch. The tool shows the combined rate whenever pitch is not zero.
Need a full walkthrough? Read the slowed reverb tutorial or compare presets on the preset guide.