Are my audio files uploaded to any server?

No. All audio slicing, waveform rendering, and MP3 encoding take place entirely inside your browser using the HTML5 Web Audio API and Web Workers. Your files never leave your device.

What audio formats can I trim?

You can trim MP3, WAV, M4A, AAC, FLAC, OGG, WebM, and AIFF audio files. You can export the result as high-bitrate MP3 or uncompressed WAV.

Can I add fade-in and fade-out effects?

Yes. You can configure smooth fade-in and fade-out durations from 0 to 5 seconds to eliminate abrupt cuts and clicks at the beginning or end of your ringtones or clips.

Audio Trimmer & MP3 Cutter: Free Online Audio Slicer

total duration • selected slice

Choose an audio file or drag it here

Supports MP3, WAV, M4A, FLAC, OGG, AAC, and WebM

Select Audio File

[

]

0:00.000

Position:

Start Time

sec

End Time

sec

Fade Effects (Curves)

Fade In:

Fade Out:

Export Settings

Configure audio format and encoding bitrate

Output Format

Bitrate Quality

320 kbps offers studio broadcast fidelity.

Slice Duration:

Est. MP3 Size:

Open Source & Privacy Guarantee

This audio trimmer uses 100% open-source Web Audio decoders and the LameJS MP3 encoder (LGPL-3.0). All sound processing is completed on your device. Zero bytes are uploaded to remote servers.

Slicing Engine: W3C Web Audio API

MP3 Library: LameJS 1.2.1 (LGPL-3.0)

Commercial Rights: 100% Royalty-Free

How to Trim and Cut Audio Online

ZetaCalculator Audio Trimmer provides high-fidelity audio trimming without uploading your personal files to third-party cloud servers. Your audio stays private on your computer or mobile device.

Upload Any Audio

Drag and drop MP3, WAV, M4A, FLAC, or OGG files into the workspace.

Adjust Start & End

Slide the visual boundary handles or enter exact millisecond coordinates with fade curves.

Export MP3 or WAV

Preview the slice and download your edited ringtone or clip with one click.