How to use Audio Trimmer
- 1Drop in an audio file — it decodes and draws as a waveform
- 2Drag the handles to select the part you care about
- 3Choose Keep to save the selection, or Remove to cut it out
- 4Add a fade in or out if the cut lands mid-sound
- 5Pick an export format and download the trimmed audio
What Audio Trimmer does
Trimming is the one audio edit where hearing the result matters more than seeing it. A cut that looks clean on a waveform can still click, because audio joined at a non-zero point creates an instantaneous jump in the signal that a speaker reproduces as a sharp transient. Judging that by eye is unreliable; judging it by ear takes a second.
So this tool is built around immediate playback. The selection loops while you drag it, which turns finding the right cut point into listening rather than measuring. The two modes behave differently under the hood for exactly that reason, and the difference is audible if you know to look for it.
When to use it
- A ringtone from a song
- Select the chorus, keep it, add a short fade at each end so it does not start or stop abruptly, and export. Most phones want something around thirty seconds.
- Silence at the start of a recording
- Voice memos and interview recordings almost always open with a stretch of room tone before anyone speaks. Selecting it and choosing Remove takes it out without touching the rest.
- A clip to quote
- Pulling ten seconds out of an hour-long podcast or lecture is quicker here than in an editor, because the selection plays on loop as you adjust it and there is no project to set up.
- Cutting an interruption
- A cough, a door, a phone ringing mid-take. Remove mode splices the surrounding audio together, and a short fade across the join hides the edit.
Audio Trimmer settings explained
- Keep
- Exports only the selected range. The preview needs no processing at all — the player is simply told to loop that slice — so dragging a handle is heard the instant you move it.
- Remove
- Deletes the selection and joins what is left. That splice has to be built before it can be played, so this preview rebuilds a quarter of a second after you stop dragging rather than instantly.
- Fade in and fade out
- Ramps the volume up from silence at the start and down at the end, in seconds. A fade of even 0.05 seconds is enough to remove the click you get from cutting through the middle of a waveform.
- Loop
- Repeats the selection continuously while you adjust it. On by default, because hearing the same passage several times is how you notice a cut landing slightly early or late.
- Zoom
- Narrows the waveform to part of the timeline so the handles move in smaller real increments. Necessary on a long recording, where one screen pixel can otherwise represent several seconds.
Keep or Remove
| Mode | What you get | Preview response | Typical use |
|---|---|---|---|
| Keep | Only the selection | Instant | Extracting a clip or ringtone |
| Remove | Everything except it | After a short pause | Deleting silence or a mistake |
Limits and what to expect
- 150 MB per file, and recordings over an hour decode slowly because samples are held uncompressed in memory.
- One selection at a time — removing several separate sections means repeating the trim.
- Cuts are made at sample boundaries, not at zero crossings, which is why the fade controls exist.
- Exporting to a format other than MP3 or WAV downloads a ~32 MB engine once, then caches it.
- Trimming a lossy file re-encodes it, so the export is a second generation unless you choose WAV or FLAC.
Troubleshooting
- There is a click at the cut
- The cut landed partway through a waveform cycle, so the signal jumps instantly to a different level. Add a fade of 0.02 to 0.05 seconds at that end — too short to hear as a fade, long enough to remove the transient.
- Remove mode does not update straight away
- That is deliberate. Removing a section means splicing and rebuilding the buffer, which is real work, so it waits until you stop dragging. Keep mode has nothing to rebuild and responds instantly.
- I cannot select precisely enough
- Zoom into the region first. On a full-length track one pixel of waveform can be several seconds, so the handles feel coarse until the view is narrowed to the part you are working on.
- The exported file is bigger than the original
- You exported to a lossless format such as WAV, which stores every sample uncompressed. Choose MP3 or M4A if size matters more than exactness — the audio is not improved by the larger file.
Your files and your privacy
The recording is decoded and edited by the browser's own audio engine inside the tab, and the waveform is drawn from the decoded samples on your device. Nothing is uploaded at any point, including during playback — the preview plays from the same in-memory buffer being edited, not from a streamed copy on a server.
What to use next
FAQ
How do I cut a song without losing quality?
Export to WAV or FLAC. Trimming itself is lossless — it only removes samples — but writing the result to MP3 or AAC re-encodes what is left, adding a generation of loss. A lossless export keeps the trimmed audio exactly as it was in the source.
Can I remove a section from the middle?
Yes, that is what Remove mode does: it deletes the selection and joins the surrounding audio. Add a short fade across the join if the splice is audible, which it often is when the cut falls in the middle of speech or a sustained note.
Why is there a click at the cut point?
Audio is a continuous wave, and cutting at an arbitrary sample almost never lands at the zero line. The instantaneous jump between the two levels is what you hear as a click. A fade of a few hundredths of a second removes it without being audible as a fade.
How do I make a ringtone?
Select roughly thirty seconds, keep it, add a fade in and out of about half a second, and export as MP3 or M4A. iPhones want an M4A of 40 seconds or less; Android is far more relaxed and accepts MP3.
Is there a length limit?
150 MB per file. Because decoded audio is held uncompressed, an hour of stereo occupies several hundred megabytes of memory regardless of how small the compressed file is, so very long recordings are best split before trimming.
Does the audio get uploaded?
No. Decoding, waveform drawing, playback and export all happen inside your browser on your own device. The tool works with the network disconnected once the page has loaded.