Free online tool

Add Reverb to a Song Online

Add reverb to any song in your browser at normal speed. Set wet mix and decay from 1.2 to 6 seconds, preview room, hall or cathedral sounds and export an MP3.

Open the free editor: upload MP3, WAV, AAC, OGG or FLAC, adjust speed, reverb, bass, tone, width and space, then export MP3 or a ZIP of many tracks. Everything runs in your browser.

Sometimes you want the room without the slowdown. A dry vocal recording that needs to sit in a space, a demo that sounds too close, a beat you want to feel bigger, a song you want to hear "from the next room" while keeping its tempo and key. This page is the editor set up for that: Speed stays at 1.00x, and you work with the two reverb controls only. The result is the original song, at the original pitch, placed in a space you chose.

The reverb is a convolution reverb. The browser convolves your audio with a synthetic impulse response, which is the recorded or generated "fingerprint" of a room, and the Space control changes how long that fingerprint rings. Everything runs locally with the Web Audio API, nothing is uploaded, and the export is an MP3. If you want the classic slowed sound with reverb included, that lives on the slowed reverb maker page. For a deeper look at the two controls themselves, see the reverb control and space, the reverb decay pages, or the guide to reverb decay and wet mix.

The two controls

Reverb is the wet mix, 0 to 100%. At 0 you hear only the original. At 100 you hear only the reverberated signal. In between it is a blend. Most useful settings are between 15% and 50%. The single most common mistake in amateur reverb is setting this too high, because a wet mix that sounds lush for the first second sounds like a bathroom after a minute.

Space is the decay time, 1.2 to 6.0 seconds. It is roughly how long the tail takes to fade after a sound stops. 1.2 s is a small room. 2.4 s, the default, is a medium hall. 4 s and above is a cathedral or a very large empty building. Decay sets the size of the imagined space; the wet mix sets how far into it you are standing.

Pre-delay is fixed at 10 ms. Pre-delay is the gap between the dry sound and the first reflection. 10 ms is a common choice because it keeps the dry transient clear and reads as a medium-sized room without sounding like an echo. It is not adjustable here. If you need a long pre-delay for a slap-back or a rhythmic effect, that is a DAW job.

There is no separate control for early reflections, damping, diffusion or pre-filtering. Two sliders, one fixed pre-delay. That is a limitation, and it is also why the tool is fast to use.

Room sizes using only Reverb and Space

Treat these as starting points. The same settings sound different on a dense mix and on a solo voice, because the mix fills the gaps the reverb would otherwise occupy.

How to add reverb to a song

1. Drop the file onto the editor. MP3, WAV, AAC, OGG and FLAC are all accepted.
2. Click Dry so that Speed is 1.00x and every other control is at zero.
3. Set Space first. Decide how big the room is before deciding how wet it is. 2.4 s is a safe middle.
4. Raise Reverb slowly while the song plays. Stop as soon as you can clearly hear the room, then back off a few percent. That last step is what separates a mix that sounds spacious from one that sounds drowned.
5. Listen to a gap. Find a pause in the song, a breath or a break between phrases, and listen to the tail. If it is still ringing when the next phrase starts, shorten Space, not Reverb.
6. Check the low end. Reverb builds up in the bass. If the low end turns to mud, pull Bass to -2 or -3 dB rather than lowering the reverb you wanted.
7. Export as MP3, or select several tracks and get a ZIP.

What a convolution reverb is

A convolution reverb takes an impulse response, which is what a room does to a single sharp click, and mathematically applies that response to every sample of your audio. If a real cathedral turns a click into a five-second decaying wash, convolving your song with that response puts the song in the cathedral. The impulse response here is synthetic: generated by the editor rather than recorded in a physical building, with its length set by the Space slider. The advantage is a smooth, dense tail at any decay time without a library of recorded rooms. The limitation is that it does not model a specific famous hall or plate. It is a clean, neutral space.

Because the impulse response is regenerated when Space changes, moving the slider while the song plays can cause a brief dip. That is normal and not in the export.

Reverb without slowing, and reverb with slowing

The same two controls appear on every page of this site, but the numbers change a lot depending on speed. At 1.00x the dry signal is tight and the reverb has to compete with it, so you need less mix for the same perceived space. At 0.85x everything is already stretched and softer, and the reverb blends in more readily, so slowed edits run at 40 to 55% where a normal-speed song would sound drowned at 35%. If you later decide you do want the slowed version, lower Speed and expect to raise Reverb by about 10 to 15 percentage points to keep the same feel.

Batch reverb

Add many files, Select All Tracks, set Reverb and Space once, and Download All gives you a ZIP. This is useful for a set of voice recordings or demos that should all live in the same room. If you want the same reverb on a whole project, save it with Create preset. Presets are kept in your browser's local storage on that device.

Export

The export is an MP3 at 96 kbps and 32 kHz, encoded in a web worker in your browser. Reverb tails are smooth, low-level signals, and 96 kbps handles them without obvious artifacts in a full mix. For YouTube, TikTok and Shorts that is fine because the platforms re-encode anyway. For a mix you plan to release, this is not a mastering tool: there is no WAV export, so do the final reverb pass in a DAW.