How it works
Read about supported files, timing, gain, fades, resampling, WAV output and memory limits.
Files and limits
Choose up to four files, each at most 20 MiB and at most 50 MiB combined. Each file must be no longer than 180 seconds, have one or two channels, and decode within a 128 MiB combined PCM budget. Output is limited to 360 seconds. These limits reduce memory use; large or unusual files can still exceed a device’s capabilities.
Decoding and output
The browser must support the input codec. Files are decoded using Web Audio at 48,000 samples per second and converted to floating-point sample arrays. Output is uncompressed signed 16-bit little-endian PCM WAV, at 48 kHz with one or two channels. Resampling and 16-bit quantization mean this is not a bit-exact or lossless copy of the source.
Trimming and joining
Trimming uses the half-open interval [start, end), with each boundary rounded to the nearest sample. Joining concatenates tracks in the displayed order without a gap or crossfade. A mono source is duplicated across left and right channels when another source is stereo. No normalization is applied.
Gain and sample peaks
Amplitude multiplier = 10^(dB / 20). For example, approximately +6.0206 dB doubles sample amplitude; −6.0206 dB halves it. Samples beyond −1 to +1 are clamped and counted. The displayed peak is a sample peak, not a true-peak or loudness measurement.
Linear fades
Fade-in rises from zero to full amplitude; fade-out falls from full amplitude to zero. Fade durations are converted to sample counts. Their sum must not exceed track duration. There is no crossfade between tracks.
Playback and privacy
Use the native audio player to listen to a source or a generated result. Playback starts only when you choose it. Clearing tracks or leaving the page releases application references and revokes temporary object URLs. Refreshing resets the workspace. Downloaded files stay on your device.