WAV Trim and Fade Tool

How to use the wav trim and fade tool

1. Choose a WAV file. It can be up to 25 MB, and uncompressed PCM and floating point files are read.
2. Enter the start and end of the part you want, in seconds or as minutes and seconds such as 1:12.5. Leave the end blank to keep everything to the end of the file.
3. Enter a fade in and a fade out in seconds, or leave them at 0 for a hard cut.
4. Read the length of the result, then press Trim and download to save a new WAV file. Nothing is played, and your original is not changed.

How the cut and fades work

The part you pick is copied sample by sample, so the result has the same sample rate, number of channels and bit depth as the original. Parts outside the fades are copied exactly, byte for byte. Nothing is compressed or converted, so there is no loss of quality from the cut itself.

A fade multiplies the samples by a gain that rises in a straight line from 0 at the first sample to full volume, or falls to 0 at the last sample. A fade is useful for removing a click at a hard cut. Fades are calculated for each channel and rounded to the nearest sample value of the file's format.

A worked example

Take a stereo file of 8,000 frames at 8,000 samples per second, one second long. Keeping 0.25 to 0.75 seconds with 0.1 second fades gives 4,000 frames (16,044 bytes with the header). The first sample of the result is 0, the 800 fades-in samples rise from silence, the 2,400 samples in the middle are identical to the original, and the last sample is 0. These values matched a separate calculation in Python.

The two fades together cannot be longer than the part you keep, and the page tells you so before you start. For checking the level of the result, use the WAV Level Analyzer.

Limits and privacy

Only WAV files are read. For MP3 or other compressed files, convert to WAV first. Files with more than eight channels, or with unusual formats such as ADPCM, are refused with a message. The file is processed on your device and nothing is uploaded. To change the speed of audio, use the Audio Speed Changer, and to estimate the size of a recording, the Video and Audio File Size Calculator.

More file tools

For level checks and PDF page sizes, try the PDF Page Size Inspector and WAV Level Analyzer.

Assumptions and limits

• The file is an uncompressed WAV file with PCM integer or floating point samples.
• Times are measured from the start of the file and rounded to the nearest sample.
• Fades are straight lines in sample value, not curves that follow how loudness is heard.
• The result is a new file saved by your browser; the original file is not changed.
• Files above 25 MB are refused so that your browser does not run out of memory.

Formulas reviewed October 10, 2026. See the calculation methodology for how SumPanda rounds, tests and sources its formulas.

Frequently asked questions