To trim an audio file, open it in an audio trimmer, mark where the part you want starts and ends, add a short fade at each end, and save the selection. Save it as WAV if you'll edit it again and as MP3 if you're sending it somewhere: a phone, a message, a website. The fades matter more than people expect. A cut in the middle of a waveform jumps straight from sound to silence, and you hear that jump as a click.
SoundGen's free audio trimmer does all of this in your browser. The file stays on your device.
Step 1: Find the part you want
Start with the waveform, not your ears. Loud passages show as tall, dense blocks and quiet ones as thin lines, so a chorus, a drum fill or a pause between sentences is usually easy to spot before you press play.
- Start a little early, then tighten. Make a rough selection, play it, and move the edges in until it begins and ends where you want.
- Cut in the gaps. Between words, between notes or just before a drum hit, the waveform is close to silent, and a cut there is nearly inaudible. Cutting across a sustained note or a word is where clicks and chopped syllables come from.
- Type the times for precision. Dragging is fast but coarse on a long file. If you know the chorus starts at 1:02.40, typing 62.40 puts the edge exactly there.
Step 2: Add fades
A fade is a short ramp in volume at the start (fade in) or end (fade out) of the cut.
- To hide the cut: a very short fade, a few hundredths of a second, removes the click without sounding like a fade at all.
- To end musically: a fade of two to five seconds lets a song trail off when the part you want doesn't end cleanly.
- For a loop or a sample: keep fades very short or leave them off, because a long fade changes how the sound hits.
Play the selection after adding fades. A fade that starts too early takes the energy out of the last line you wanted to keep.
Step 3: Save it in the right format
| WAV | MP3 | |
|---|---|---|
| Quality | Exactly what was decoded, nothing lost | Encoded again; a little is lost each time |
| Size | Large (about 10 MB a minute for CD-quality stereo) | Small (about 1.4 MB a minute at 192 kbps) |
| Best for | Editing further, music software, samples | Phones, messages, uploads, ringtones |
If your source was an MP3 and you save the cut as MP3, it has been encoded twice. At a decent bitrate that is hard to hear, but if you plan to edit the clip again, keep a WAV copy and make the MP3 from that.
Turning the clip into a ringtone
Make the cut first: pick the hook or the intro you want to hear when the phone rings, fade the ends, and download it as MP3.
On Android
Google's help describes two ways:
- With Files by Google: open the Files by Google app, go to Audio under Categories, find and play your file, then tap More and Set as ringtone. You'll be asked to allow the app to modify system settings.
- From a computer: connect the phone with a USB cable and copy the MP3 into the phone's Ringtones folder. Then open Settings, go to Sound & vibration, tap Ringtone and pick it.
Menu names vary between phone makers and Android versions, so yours may be worded a little differently.
On iPhone
Apple's documented route goes through its free GarageBand app, and Apple says ringtones can be up to 30 seconds long. Trimming to 30 seconds or less first means GarageBand has nothing to shorten:
- Save your trimmed file to the Files app.
- In GarageBand, start a new audio recording project and open Tracks view.
- Open the Loops Browser, choose Files, and drag your clip to the very start of the track, with no gap before it.
- Go back to My Songs, select the project, tap Share, then Ringtone, name it and tap Export.
- Choose Use sound as to set it as your ringtone, a text tone or a contact's ringtone.
Other ways to trim audio
- A desktop audio editor (Audacity, or the editor built into most DAWs) does the same job with more options, and is worth installing if you trim files every day.
- In a project: in the SoundGen studio, drag a clip's edges to trim it and its fade handles to fade it. The original file is untouched, so you can change your mind later.
FAQ
Can I trim an MP3 without losing quality? Only with a tool that cuts the MP3 frames directly, without decoding, and those can only cut at frame boundaries (about 26 ms apart at 44.1 kHz). A tool that decodes and saves again, as most browser trimmers do, re-encodes the MP3. Save as WAV if you want no further loss.
Why does my cut click at the start or end? The cut lands mid-waveform, so the sound jumps from a value to silence. Add a fade of a few hundredths of a second, or move the edge to a quieter spot.
How long should a ringtone be? On iPhone, Apple's GarageBand route allows up to 30 seconds. Android's help doesn't state a limit. Either way, the part people recognise in the first few seconds matters most, so start the cut on the hook rather than on a slow intro.
Is it safe to trim a private recording online? With a browser-based tool that processes the file on your device, like SoundGen's audio trimmer, nothing is uploaded. Tools that upload to a server can't promise that.
SoundGen Team
Written by the team building SoundGen
