How to use the MP3 cutter
- Open a file. Drop it on the box or press the box to choose one. MP3, M4A, WAV, FLAC and most video files work.
- Pick the part. Drag the two handles on the waveform, or type exact times in Start and End, such as 1:12.50. Zoom in for precise cuts.
- Listen. Press Play selection, or Preview cut point to hear 1.5 seconds either side of a handle.
- Add fades if the cut starts or ends in the middle of the music. One to three seconds sounds natural for songs.
- Choose a format and press Save. MP3 at 192 kbps suits most uses; WAV keeps full quality.
To cut a mistake out of the middle of a recording, choose Remove selection: the cutter keeps both sides and joins them. It also works as an MP3 clipper for sharing a few seconds of a song or a voice note.
With the editor focused, Space plays and stops, I and O set the start and end at the playhead, and the arrow keys move a focused handle by 0.1 seconds (1 second with Shift).
How the MP3 trimmer works
The MP3 trimmer doesn’t send your file anywhere. Your browser decodes it into raw audio, 44,100 samples per second for each channel, and the page keeps it in memory while you edit. When you press Save, it copies the samples between the handles, applies the fades and encodes a new file on your device.
That last step matters for quality. MP3 is a lossy format, so decoding and re-encoding one adds a small generation loss, a bit like photocopying a photocopy. At 192 kbps or higher, most listeners can’t hear the difference. If you’ll edit the file again, save it as WAV: it isn’t compressed, so nothing more is lost, but it takes seven to ten times the space. The estimate next to Save shows how big the file will be.
Which bit rate? 128 kbps is fine for speech and podcasts, 192 kbps for most music, and 256 or 320 kbps when the source was high quality and you want to keep as much as possible. A higher rate than the source can’t add quality back. Normalize raises the loudest peak to −1 dB, which helps quiet recordings; leave it off for music that’s already mastered.
Fades, cut points and clicks
A sound wave swings above and below zero hundreds of times a second. If a cut lands while the wave is far from zero, the sudden jump makes a click. The cutter avoids that in two ways. With Snap to zero crossing on, a handle you drag moves to the nearest point within 5 ms where the wave crosses zero. And even with no fade set, it adds a 5-ms micro-fade at each end, too short to hear as a fade.
For music, a real fade sounds better than a hard stop: one to three seconds at the end of a song clip, and a short fade in of a few tenths of a second if the cut starts mid-note. Fades follow a gentle curve and play exactly as they’ll be saved.
In Remove selection mode, the two sides meet with a 10-ms crossfade, so the joint doesn’t click either. Press Preview cut point to hear the joint before you save. If a word is clipped, move a handle by 0.1 seconds and listen again.
Files the audio cutter can open
This audio cutter opens anything your browser can decode: MP3, M4A and AAC, WAV and, in most browsers, FLAC and OGG. It can also take the sound track from MP4 and WebM videos. Protected files, such as Apple Music downloads, can’t be opened. Mono files stay mono, and files with more than two channels, such as a 5.1 video sound track, are mixed down to stereo.
Files can be up to 15 minutes long, or 10 minutes on phones and tablets, and up to 200 MB. The limits exist because the whole decoded file sits in memory: a minute of stereo audio takes about 21 MB once decoded, whatever size the MP3 was. For a longer file, use a desktop editor. Need the tempo of the part you kept? Drop it on the BPM finder.
Saving on a phone
On an iPhone, Safari saves downloads to the Files app, in the Downloads folder. Share sends the file straight to another app instead, such as Messages or a cloud drive. On Android, the file lands in Downloads. To use it as an alarm or notification sound, pick it in your phone’s sound settings, or move it with the Files app first.
Making a ringtone?
The ringtone maker is built for this job: a 30-second window, fades that suit a ringtone, an iPhone M4R file or an Android MP3, and the steps to install it. To cut a recording you haven’t made yet, start with the online voice recorder, then open the file here.