Audio trimmer
Cut a section out of a track on a real waveform, with the two points where you put them and the result on screen before you save. An MP3 is copied out frame by frame instead of being decoded and encoded again, so what you get back is the audio that went in.
- An MP3 trim copies the frames out, so it costs nothing in quality
- A waveform you can zoom into, so a cut can go between two words
- No 250 MB cap and no two-hour file retention, because there is no server
- No watermark, no ads, no account, and it works offline
MP3, WAV, M4A, AAC, OGG, FLAC, Opus and WebM.
A three-hour recording opens as fast as a ringtone, because nothing is uploaded.
- Length
- —
- Size
- —
Free, no sign-up, nothing uploaded. There is no 250 MB cap, because there is no server paying for the bandwidth. An MP3 is cut on its own frame boundaries, so the audio you keep is the bytes that were already in the file.
How to trim an audio file
Drop an audio file in
MP3, WAV, M4A, AAC, OGG, FLAC or Opus. Nothing is uploaded, so a two-hour recording opens without a progress bar.
Drag the two points on the waveform
Pull the handles, or type the times, or press I and O while it plays. Zoom in to put a cut between two words, and loop the selection to check it.
Check the badge, then save
The strip says whether the export is lossless, what it will weigh, and why if it is not. An MP3 comes out as the frames that went in.
Six ways to place the two points
| Way | How | Best for |
|---|---|---|
| Drag | Pull a handle on the waveform | Finding it by eye |
| Type | Enter 1:23.500 in Start or End | A time you already know |
| I and O | Press the key while it plays | Finding it by ear |
| Arrows | 10 ms, or 1 s with shift, or 1 ms with alt | The last few milliseconds |
| Length | Type a duration; the end moves | A clip that has to be exactly 30 s |
| Snap | Pick a preset length | Ringtones, stories, voicemail |
Double-clicking the waveform selects the whole file again.
Why most MP3 cutters make your file worse
An MP3 cutter has two ways to do the job. It can decode the whole file to samples, throw away the part you did not want, and encode what is left. Or it can find the frame boundaries either side of your selection and copy those bytes out.
Almost every one online does the first. That second encode is a second generation of loss, applied to audio you never asked to have re-processed, and it happens even when you are trimming one second of silence off the end of a three-minute track. The frequencies the first encoder discarded are gone either way; the second pass then goes to work on what survived and picks a slightly different set of things to throw away.
This one does the second, whenever it can. It is not a better encoder. It is no encoder at all. The strip above the save button tells you which path you are on before you commit to it.
The one thing a frame copy cannot do
Land the cut exactly where you put it. An MP3 frame holds 1152 samples and cannot be split, so the in-point moves to the nearest frame boundary. At 44.1 kHz that is a quantum of 26.122 milliseconds; at 48 kHz it is 24 milliseconds.
In practice that is under half the length of a spoken consonant, and well inside the gap between two words. It matters for exactly one job, cutting a loop that has to line up to a beat, and for that the answer is to save as WAV and accept the size.
Rather than rounding your number silently, this tool reports where it actually cut when you save: cut at 0:02.978 and 0:07.001, the nearest frame boundaries.
Zoom, and why a cutter needs it
At a typical 1200 pixels wide, a three-minute track puts about 150 milliseconds in every pixel. That is longer than a whole syllable. Dragging a handle at that scale, you cannot see the gap between two words, let alone land in it.
So the waveform zooms. Scroll to zoom around the pointer, or use the slider, or press
+ and −. Past 1× an overview strip appears above it so you still know
where you are in the file, and 0 fits the whole thing back on screen.
Fades, and what turning one on costs
A fade changes the sample values themselves, and sample values cannot be changed inside a compressed frame without decoding it. So any fade above zero turns the lossless path off, and the format control moves to WAV in front of you rather than after the fact.
The curve is equal-power, a quarter sine, rather than a straight line. A linear fade sounds like it stalls in the middle, because loudness is not linear in amplitude and the ear hears the halfway point of a straight ramp as far quieter than half.
Questions
Does this re-encode my MP3?
Not unless something forces it. Cutting an MP3 to an MP3 with no fades copies the frames byte for byte. Adding a fade, or saving a non-MP3 as an MP3, needs a decode, and the strip above the save button says so before you press it.
How accurate is the cut?
To the nearest frame boundary on the lossless path: 26.122 ms at 44.1 kHz, 24 ms at 48 kHz. Exact to the sample if you save as WAV.
Is there a size limit?
No upload limit, because there is no upload. The practical ceiling is memory: drawing a waveform needs the decoded audio in RAM, which is roughly three hours of stereo on a normal machine.
What can I save as?
MP3, when the source was an MP3 and nothing forces a decode. Otherwise WAV at 16, 24 or 32-bit float. There is no MP3 encoder in any browser, which is why the lossless path is the only way to get an MP3 out of this.
Can I cut the middle out instead?
Yes. Switch the selection to What I cut out and the two ends are joined. On an MP3 that is still lossless: it is one byte range plus another.
Does it work on a phone?
Yes. The waveform takes touch, and the handles are draggable. Typing the times is easier on a small screen than dragging.
Do you keep my audio?
There is nowhere to keep it. The file is read by your own browser and never sent anywhere. You can watch the network panel stay empty while you use this.