Add Reverb to Audio

Reverb is what tells a listener where a sound happened. This tool builds the acoustics of a space and applies them to your recording, with the decay time set in seconds and measured on the file you download.

A close-miked voice or a direct-recorded instrument carries no room with it, which is why it can sound flat and detached next to material that does. Reverb supplies the missing space: the early reflections that tell the ear how large the room is, and the diffuse tail that follows them. Used lightly it makes a dry recording sound like it belongs somewhere. Used heavily it becomes an effect in its own right.

• Vocals: a short room at a low wet level puts a dry take in a believable space without pushing it back.
• Instruments: a plate or chamber glues a layered arrangement together, which is what plates were built for.
• Voice-over and podcast: a small studio setting adds warmth to an over-treated booth recording.
• Sound design: a cathedral at a long decay turns a short sample into an atmosphere.

Five of the spaces are modelled as rooms with real dimensions, so their early reflections arrive at times set by geometry rather than by a preset table — the reflections in a cathedral arrive late and sparse because a cathedral is large. The remaining two are not rooms at all and say so.

• Studio a small treated space. Tight, dry and short — the default is 0.4 seconds.
• Room an ordinary domestic room, with strong early reflections and a 0.8 second tail.
• Chamber a larger hard-walled space, denser and longer at 1.4 seconds.
• Hall a concert hall: sparse early reflections, a noticeable build-up, and 2.2 seconds.
• Cathedral very large and very absorbent-free, with a long build-up and a 5 second default.
• Plate no early reflections, immediate density and a bright tail. The classic studio effect.
• Spring dispersive: every reflection arrives smeared downward in pitch, which is the sound of a spring tank.

Most reverbs give you a decay control and ask you to trust it. This one measures what it produced. After processing, a test impulse is sent through the identical chain — the same space, the same damping, the same clip guard, the same output rate — and the rate at which its energy falls is read back using the standard acousticians apply to real rooms. The number beside your result is that measurement, not the number you typed.

It matters because the two can genuinely disagree. Damping makes high frequencies fade faster than low ones, so the overall decay is no longer a single simple curve, and a tool that assumed otherwise would report a time the file does not have. Measured across every combination of space, decay time, damping, early level and width, the finished file lands within 2% of the requested time above one second, and within 3.5% below it.

A reverb tail outlasts the sound that caused it. That means the output has to be longer than the input, and a tool that does not extend it simply cuts the reverb off mid-decay — which is what the page this replaces did. Here the file is extended by the length of the tail by default, so a 3 second clip with a 2 second decay comes back a little over 5 seconds long. If you need to preserve the original length, the trim option keeps it.

• Decay how many seconds the tail takes to fall away, from 0.2 to 10.
• Wet and dry how much reverb and how much original sit in the mix. They are independent levels, not one blend control.
• Pre-delay the gap before the first reflection. Raising it keeps a vocal in front of its own reverb.
• Damping how much faster the treble fades than the bass, and the frequency where that starts. It applies to the tail only.
• Early reflections how much of the room's first bounces you hear against the diffuse tail.
• Diffusion how dense the tail is. Low is grainy and small; high is smooth, which is what a plate sounds like.
• Stereo width how far apart the two sides of the tail are, from centred to fully spread.
• Clip guard holds the finished file at or under a true-peak ceiling, since reverb adds energy.

• Start with less than you think: wet around 20–30% is where most mixes sit. Reverb is easy to over-apply because you stop noticing it.
• Use pre-delay for clarity: 20–30 ms keeps speech intelligible while still placing it in a space.
• Match the decay to the tempo: a tail that outlasts the gap between notes turns detail into wash.
• Damp the highs for realism: no real room reflects treble as long as it reflects bass, so a bright infinite tail always sounds synthetic.
• Check the measured number: if it differs from what you asked for, the tail genuinely is what the measurement says.

Bring MP3, WAV, FLAC, OGG, Opus, M4A or AAC, or an MP4, MOV, MKV or WebM and the audio track will be taken from it. Save as MP3, WAV, FLAC, OGG, AAC or M4A. Anything the tool cannot open is refused the moment you pick it, with a link to the converter — you never reach a progress bar that then fails. Free covers one file at a time up to 50 MB and ten minutes, at 44.1 kHz and 192 kbps. Pro raises that to 25 files at once, 48 kHz, 320 kbps and 24-bit WAV.

Your audio is processed where it already is. No file is uploaded, nothing is stored, and the tool keeps working if the connection drops after the page has loaded. That is also why it is fast on long files: there is no round trip to wait for.

Powered by optimised audio processing algorithms.

• Audio echo
• Audio equalizer
• Audio normalizer
• Audio compressor
• Audio converter