Audio Trimmer - Cut MP3 & Audio Files Online

This trimmer cuts a section out of any audio file your browser can play — MP3, M4A/AAC, OGG/Opus, FLAC, WebM, or WAV — and saves just that section as a new file, without installing software and without uploading anything. It borrows the browser's own media engine: decodeAudioData unpacks the compressed file into raw samples using the same battle-tested decoders that power the audio tag, the waveform is drawn from those samples so you can see exactly where words, beats, and silences fall, and the export re-encodes only the samples between your two markers. The waveform view itself is rendered with wavesurfer.js, the open-source (BSD-3-Clause) waveform library used across the audio web. You can set the selection two ways, and they stay in sync. The shaded region on the waveform is the part you keep: drag its body to slide the whole selection along the file, or grab either edge to resize it — everything outside the region is discarded. The Zoom slider stretches the waveform to hundreds of pixels per second and scrolls, so a single syllable or drum hit becomes easy to bracket by eye. The Start and End fields mirror every region move and let you refine the cut to the exact hundredth of a second, which matters when you are isolating a single word from a voice memo or cutting a loop that must land precisely on a beat — type a value and the region snaps to match. The fade fields solve the most common problem with hard cuts: clicks. When a cut lands mid-waveform, the audio jumps instantly from silence to some non-zero sample value, and that discontinuity is audible as a pop. A short fade-in and fade-out — even 5 to 20 milliseconds — ramps the volume smoothly through the cut points and removes the click without being audible as a fade. Longer fades, from half a second to several seconds, are a stylistic choice: a two-second fade-out is the classic way to end a music excerpt that would otherwise stop abruptly. For output, WAV is a bit-exact 16-bit PCM copy of the selection and the right choice when the cut is headed into an editor, a sampler, or another tool. MP3 at 192 kbps is the right choice for sharing — small, universally playable, and transparent for most material — but remember that every MP3 encode is one lossy generation, so if you plan to trim again later, keep a WAV master. Because everything runs locally, a long recording trims in seconds with no upload wait, no file-size cap beyond your device's memory, and no privacy trade-off: the audio never leaves your machine.