Cut a piece out. Stitch it back together.
Select the cough, the pause or the fumbled take on the waveform and press cut. The two sides are rejoined with a micro crossfade, so there is no click at the seam.
Nothing is uploaded, so there is no queue, no size tier and no waiting on a slow connection. The work happens on the device you are reading this on.
A WAV editor, an M4A editor and an MP3 editor, all the same tool
There is no separate tool to pick here. The editor opens whatever your browser can decode, so editing a WAV file, an M4A from an iPhone, an MP3, an OGG or a FLAC all work the same way: drop it in, cut what you do not want, save. AMR voice memos from a phone open too, which most browser editors cannot manage.
One thing is worth knowing before you start, because it surprises people. Editing happens on the decoded audio in memory, so the parts you keep are not re-compressed while you work. Saving is where the format is decided, and the two encoders that fit in a web page are WAV and MP3. A WAV in can be a WAV out, with nothing lost anywhere in the round trip. An M4A, OGG or FLAC goes in and comes out as WAV if you want to keep every bit, or MP3 if you want it small. What you cannot do is edit an M4A and get an M4A back.
How to cut a section out of an audio file
- Open the editor and drop your file in. The waveform appears, and quiet recordings are automatically magnified so you can see what you are doing.
- Drag across the part you want gone. Play just the selection, on loop if you like, and nudge the edges by a tenth of a second until it is exact.
- Press cut and stitch (or just the Delete key). The gap closes with a 4 millisecond crossfade, so the seam does not click or pop.
- Undo if it was wrong; every edit is reversible. Export as MP3 or WAV when the take is clean.
More than a trimmer
- Trim to selection throws away everything outside your selection: top and tail a recording in one move.
- Silence a section without shortening the file, for when timing matters.
- Split a file in two: place the playhead and export each side as its own file.
- Fades and inserted silence for clean starts, ends and breathing room.
Where to cut, so the join is invisible
The seam itself is handled for you: the two sides are rejoined with a four millisecond crossfade, which removes the click a raw cut leaves behind. What software cannot decide is where to cut, and that is what separates an edit nobody notices from one everybody does.
- Cut in the gaps, not through words. Silence splices into silence invisibly. Cutting mid-vowel is audible in any editor ever made.
- Leave the breath in. Removing every inhale makes speech sound synthetic and airless. Take out the long ones, keep the short ones.
- Watch the room tone. If one side of your cut has a fan humming and the other does not, the join announces itself. Removing the noise first makes cuts far more forgiving.
- Land just before a hard consonant. The moment before a t or a p is the cleanest place for a boundary.
Working quickly
The fastest loop, once it is habit: drag a rough selection, tick Loop, press play, then nudge the selection edges with the -0.1 and +0.1 buttons while it repeats until the boundary sounds right. Then press Delete. You are hearing exactly the region that is about to disappear, so there is no guessing.
Worth memorising: space plays and pauses, delete cuts the selection, ctrl+z undoes anything including noise removal, a selects the whole track, f fits the view. Selections can also be typed exactly, in either 1:23.500 or plain seconds, when you already know your timestamps.
Beyond simple trimming
| You want to | Use |
|---|---|
| Remove a cough or a fumble | Select it, cut and stitch |
| Keep only the good middle section | Select it, trim to selection |
| Mute a noise but keep the timing intact | Select it, silence selection |
| Split a long recording into two files | Place the playhead, export each side |
| Lift one section out to use elsewhere | Select it, send it to the file list |
| Make room for something to be inserted | Insert silence at the playhead |
If a cut sounds wrong
Undo and listen again with the loop trick above. Nine times out of ten the selection was a fraction too wide and took the start of the next word with it. If the seam clicks despite the crossfade, you have almost certainly cut through the middle of a sustained sound rather than in a gap.
Common questions
Can I edit a WAV file without converting it to something else?
Yes. A WAV opens, edits and saves back out as WAV, and nothing is re-compressed along the way, so the audio you keep is exactly what you started with. That round trip is the one case where editing costs no quality at all.
Is there an M4A editor that does not upload my file?
This is one. M4A files from iPhones and voice recorder apps open directly in the browser and can be cut, faded and joined. The only limit is on the way out: you save as MP3 or WAV rather than back to M4A, because those are the two encoders that fit in a page with nothing to install.
Will there be a click where I cut?
No. The two sides are rejoined with a short crossfade, which removes the click a hard cut would leave. Cutting through the middle of a vowel is still audible in any editor, so cut in the gaps.
Can I see the waveform of a quiet recording?
Yes. The display auto-magnifies quiet recordings and tells you the magnification, so even a whispered phone memo is visible and editable.
How precise can I get?
Zoom goes down to individual samples, selections can be typed to the millisecond, and nudge buttons move edges by a tenth of a second.
Can I undo a bad cut?
Yes. Every edit, including cuts, noise removal and levelling, is undoable, and a toast with an undo button appears right after each one.
Next door
Trim a file now
Drop the file in and it opens ready to work on. No account, no queue, and it never leaves your machine.