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Lizely

Audio Effects Online

Apply one deterministic echo, lightweight reverb, reverse, fade, or normalization effect locally and download the complete PCM16 WAV.

Privacy: your files never leave your device. All processing happens locally in your browser.

How to use

  1. 1.Choose one browser-decodable audio file no larger than 50 MiB.
  2. 2.Select echo, lightweight reverb, reverse, fade in, fade out, or normalization and set a whole-number amount from 0% through 100%.
  3. 3.Apply the effect locally, inspect frame counts and peak, then download the PCM16 WAV while keeping the untouched original.

About Audio Effects Online

Audio Effects Online applies one selected transformation to a browser-decodable audio file and downloads the complete result as PCM16 WAV. The available choices are a single 200 millisecond echo, lightweight three-tap reverb reflections, reverse, fade in, fade out, and peak normalization. An amount control from zero through one hundred percent blends or scales the chosen operation. The page reports channel count, sample rate, input and output frame counts, output peak, and exact WAV byte size after processing.

Input decoding uses the browser Web Audio implementation. MP3, WAV, M4A, AAC, Ogg, WebM, and FLAC names are accepted, but actual codec and profile support varies by browser and operating system. A recognized filename does not guarantee that a particular encoded file will decode. If decoding fails, the tool creates no result. One encoded file may be at most fifty MiB, and decoded data must remain within the declared channel, sample-rate, duration, and channel-sample budgets inherited by the local audio pipeline.

Echo is deliberately simple and reproducible. At one hundred percent amount, each input sample is retained and a half-strength copy is added two tenths of a second later. Lower amounts scale the delayed copy linearly. The complete delayed tail is allocated before processing, so the last echo is not cut off. Reverb is a lightweight early-reflection design rather than a room simulator: copies are added at 29.7, 37.1, and 41.1 milliseconds with disclosed weights of 0.50, 0.35, and 0.25 multiplied by the selected amount.

Those echo and reverb coefficients are Lizely product choices, not measurements of a concert hall, plate, spring, studio, impulse response, acoustic material, or branded processor. The result can add space or repetition for a quick sound-design draft, but it does not model room dimensions, frequency-dependent decay, stereo diffusion, damping, pre-delay, convolution, or a professional reverberation tail. Strong settings can clip when dry and delayed samples overlap; output samples are therefore constrained to the legal -1 through +1 floating range before WAV quantization.

Reverse reads the sample frames in the opposite order and blends them with the original according to amount. Fade in scales from the selected dry proportion at the beginning to full level at the end, while fade out performs the inverse. Normalization finds the largest absolute decoded sample and scales toward a 0.95 peak. Normalization is not loudness matching: it does not target LUFS, perceived volume, broadcast compliance, dynamics, true peak between samples, or equal loudness across different recordings. Silent input stays silent.

The downloadable file is a new interleaved little-endian PCM16 RIFF/WAVE. Microsoft documents PCM block alignment as channels multiplied by bits per sample divided by eight; at sixteen bits this produces two bytes per mono frame and four bytes per stereo frame. The W3C Web Audio specification defines decoded AudioBuffer length in sample frames and the browser decoding contract used here. Tests independently lock PCM frame arithmetic plus all disclosed effect delays, weights, blends, limits, and tail sizes.

Export does not preserve the source codec, bitrate, compression quality, tags, artwork, chapters, cue points, loop markers, or container metadata. Floating samples are quantized to signed sixteen-bit PCM. The tool also applies only one effect per run; to build a chain, download a result, inspect it, and use that WAV as a later input. Repeated lossy decode and PCM processing may reveal source artifacts, and repeated clipping or normalization can change dynamics. Keep an untouched original file.

Resource and concurrency boundaries are explicit. The decoded input and complete effect output may each contain no more than thirty million channel samples. Echo and reverb can pass the input budget yet fail the output budget because their tails add frames; in that case nothing is truncated and no file is created. Changing the file, effect, or amount invalidates older work. Decode contexts are closed, stale jobs cannot replace newer state, and temporary object URLs are revoked on replacement and unmount.

All file reading, decoding, sample processing, WAV encoding, and download creation happen in the current browser tab. Audio is not uploaded to Lizely or stored in an account. There is no server render and no hidden AI transformation. The reliable contract is narrow: decode one supported file, apply the exact disclosed operation to every frame, preserve the complete calculated tail within budget, encode a standards-based PCM16 WAV, and state clearly what the lightweight effect does not claim to emulate.

Methodology & sources

Validate one local browser-decodable audio file, decode it with Web Audio, and require 1-8 equal-length channels, 8,000-192,000 Hz, an integer 0-100 effect amount, and no more than 30 million channel samples. Apply one deterministic operation: 200 ms half-strength echo; three disclosed reverb taps; reverse blend; full-range linear fade; or scale toward 0.95 sample peak. Allocate the complete echo/reverb tail before processing, reject output above 30 million channel samples without truncation, clip finite samples to -1 through +1, and reuse the separately tested PCM16 WAV encoder. Job identity, AudioContext cleanup, and Object URL revocation prevent stale results and leaks.

Frequently asked questions

Is the reverb a real room or studio processor emulation?
No. It is a disclosed lightweight three-tap reflection design at 29.7, 37.1, and 41.1 milliseconds. It does not model a room, impulse response, diffusion, damping, or professional hardware.
Does normalization make different files equally loud?
No. It scales toward a 0.95 sample peak. It does not measure LUFS, perceived loudness, dynamics, or inter-sample true peak.
What does the download preserve from my original file?
It preserves the processed channel samples and sample rate in a new PCM16 WAV. Original compression, tags, artwork, chapters, and other container metadata are not preserved.

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