Audio Cutter – Cut and Trim MP3 Online Without Uploading

Drag in an audio file, select a range on the waveform or by typed start/end seconds, then remove or keep just that portion.

The cutter decodes a file to raw samples, lets you mark a range on the waveform by dragging or by typing exact start and end seconds, and then either removes that range (splicing what's left together with no gap) or keeps only that range and throws the rest away. Both operations run against the decoded signal, so the selection boundary lands on an exact sample, not a rough click.

How to cut an MP3 online

  1. Drop one audio file on the upload area, or click it to browse; the cutter decodes the file and draws its waveform.
  2. Drag across the waveform to mark a range, or type exact Start and End values in seconds — click anywhere to preview from that point.
  3. Click Remove selected portion to delete the range and close the gap, or Keep only selected portion to throw away everything around it; Undo last cut steps back one edit.
  4. Under Export, pick WAV, FLAC, MP3 (64–320 kbps), AAC (M4A) or Ogg Opus, then download the result, saved under your original name with -cut added.

What happens between drop and playback

A dropped file is decoded through the browser's own AudioContext for WAV, MP3 and AAC, through a bundled libflacjs WebAssembly build for FLAC, and through the WebCodecs decoder for Opus-in-Ogg. That decode step is what makes sample-accurate cutting possible in the first place: once the file is a set of Float32 channel arrays, a boundary is just an index computed as seconds multiplied by sample rate and rounded to the nearest whole sample.

Clicking anywhere on the waveform seeks a preview from that point; dragging defines or redraws the selected region, and the numeric start/end fields stay in sync with whatever you dragged. Selections are clamped automatically to the file's own duration, so a region typed past the end or before the start snaps back into range instead of erroring.

Remove versus keep

Removing ripple-deletes the marked span: everything after it shifts earlier to close the gap, and the result is shorter by exactly the region's own length. Keeping does the opposite — it discards everything outside the marked span and returns only what was inside it. Trying to remove a region that covers the entire clip is rejected outright, since nothing would be left to export; the same goes for keeping a region with zero width.

Files the audio cutter can open

Export formats and what they cost you

Cutting a short clip for a ringtone

For a ringtone or alert sound, mark the 20 to 40 seconds you want, press Keep only selected portion, and export as M4A (AAC at a fixed 128 kbps) or MP3. The cutter has no .m4r export, so it never produces a file already packaged as an iPhone ringtone, and we have not tested whether renaming an .m4a to .m4r is accepted — follow your phone's own instructions for installing a tone.

There is no fade control here either: the clip starts and stops on exactly the samples you selected. For a gentle start or ending, export the clip as WAV, open it in the Audio Volume Changer, set its fade-in and fade-out fields (each accepts up to 5,000 milliseconds), and export the final format from there.

The one thing this isn't

A cut here is never a byte-level trim of the original compressed stream — the file is fully decoded, edited as PCM, and re-encoded on export even if you started and ended with the same format. That means cutting an MP3 and exporting it back to MP3 still passes through one additional lossy encode pass, which is unavoidable given how the selection needs to land on an arbitrary sample rather than a codec frame boundary. If you need a truly lossless trim of a compressed file with no re-encode at all, this is the wrong tool for that specific case.

Nothing leaves your device

Decoding, cutting and re-encoding all run in the browser tab itself — no file, waveform, or exported clip is sent anywhere. The MP3 encoder is program code fetched from this site the first time you export an MP3, so stay online until then; that download carries code to you and never carries your audio out.

Cutting exports are free for 15 files a day, with Pro unlimited.

Questions people ask about Audio Cutter

Can I cut audio from a video file?
The cutter is built for audio, and its file picker lists only audio types such as WAV, MP3, FLAC, M4A, AAC, Ogg and Opus. For an MP4, MOV or WebM video, pull the soundtrack out with the Audio Extractor first, save it as WAV to avoid an extra lossy pass, then cut that file here.
Can I add a fade in or fade out?
Not in the cutter. Both Remove and Keep splice on exact samples with no volume ramp, so an edit made in the middle of loud audio can sound abrupt. Run the finished clip through the Audio Volume Changer, whose fade-in and fade-out settings go up to five seconds each.
Can I make a ringtone with it?
You can cut the clip; installing it is up to your phone. Keep the section you want and export M4A or MP3. The cutter does not create .m4r files and cannot fade the ends, and we make no claim that any particular phone accepts a renamed file.
Does it work on my phone?
It runs in a mobile browser like any web page, so the answer depends on that browser. Decoding uses its Web Audio support, AAC and Opus exports need its WebCodecs audio encoder, and the whole decoded file sits in memory, which phones have less of than computers.
Is there a file size limit?
There is no fixed size cap. The file is decoded into 32-bit samples held in memory, about 1.27 GB per hour of stereo 44.1 kHz audio, so very long recordings are limited by your device's RAM. The free-tier limit applies to exports instead: 15 audio files per day, shared with the converter and joiner.
Why does my MP3 sound slightly different after cutting even though I picked MP3 as the output?
Cutting works on fully decoded audio, not the original compressed frames, so the file goes through a fresh MP3 encode on export no matter what format it started as. A second lossy encode pass on already-lossy audio introduces a small amount of additional quality loss — usually not audible, but it is real and it is unavoidable with sample-accurate cutting.
Can I select a region shorter than a second?
Yes. Selection boundaries are computed in samples, so at a typical 44.1kHz or 48kHz sample rate you can mark a region a few milliseconds wide. Typing exact start and end values in the numeric fields is more reliable than dragging for very short selections.
What happens if I try to remove the whole clip?
The tool refuses and leaves the file unchanged, because removing every sample would leave nothing to export. Narrow the selection first, or use the keep-only mode instead if your goal was actually to isolate a small piece rather than delete everything.
Does the cutter preserve the original file's tags?
Yes, for the common fields. The cutter reads the source's title, artist, album, track number, year, genre and embedded cover art, and writes them into the exported clip. The only gap is cover art on WAV output, because WAV's RIFF INFO tags have no slot for a picture.

Related tools on BrakeTools

Content reviewed 2026-09-27.