Free tool
Audio trimmer
Drop a recording into this audio trimmer, drag the two handles on its waveform to where the sound you want begins and ends, and save. An MP3, M4A, WAV or FLAC comes back in the same format, not re-encoded.
- Free
- No re-encoding for MP3, M4A, WAV, FLAC
- Nothing is uploaded
Drop your audio file here, or Choose your audio file
MP3, M4A, WAV, FLAC, OGG, AAC, or the sound of an MP4, MOV or WebM video, up to 1 GB and 2 hours. Everything happens in your browser; nothing is uploaded.
MP3 encoding by LAME, open-source software.
Trimming a recorded call or lecture before going through it? NoteOwl transcribes recordings on your Mac with each speaker labelled, so you read and search what was said instead of scrubbing.
How it works
How do you trim audio?
Add the file and wait a moment while its waveform appears. Drag the left handle to where the part you want begins and the right one to where it ends, or type both times. Play the selection, then press Trim audio and download the new file.
- 1
Add the recording
Drop it on the box or choose it. A voice memo, a podcast, a WAV from a recorder or the sound of a video all work.
- 2
Move the two handles
Drag them, nudge them by a tenth of a second, or let the trimmer find where the sound starts and stops.
- 3
Trim and download
The file keeps its name with “-trimmed” added, in the same format as the original unless you pick MP3 or WAV.
What does trimming take off?
Only the two ends: whatever is before the left handle and after the right one. Everything between them stays as one piece. That suits the usual clean-up of a recording: the seconds before anyone spoke, and the rustle after you meant to stop.
To lift a part out of the middle, use the MP3 cutter, which can cut a selection out and close the gap. To turn one long recording into several files, use the audio splitter.
Dead air at the start
The silence while a phone was set down, or a meeting waited for people to join.
Chatter at the end
Goodbyes, a recorder left running, a door, someone asking whether it’s still on.
A false start
The first attempt at an answer or a take, when the one you want begins a minute in.
Does trimming audio lower its quality?
Not for MP3, M4A, WAV, FLAC or OGG files: to trim MP3 and the others, the trimmer copies the original’s own sound into the new file instead of encoding it again, so nothing changes. A 1:00 cut from a 74 MB WAV came out sample for sample identical.
Compressed files are cut on their own frames, which are a fortieth of a second or so long. In our test the trimmed MP3 began 0.06 seconds before the point we set, because the first frame needs the one before it to decode. WAV is cut to the exact sample.
- MP3
- What you getMP3, frames copied
- Measured0:30–1:30 of a 6:44 podcast gave 60.08 s
- M4A (AAC)
- What you getM4A, sound copied
- MeasuredA 3:00 voice memo trimmed in under 0.1 s
- WAV, 16 or 24-bit
- What you getWAV, every sample kept
- Measured1:00–2:00 gave exactly 60.000 s, identical samples
- FLAC, OGG
- What you getThe same format, copied
- MeasuredA FLAC stayed FLAC
- MP4 or MOV video
- What you getAn M4A of its sound
- MeasuredA screen recording gave an AAC M4A, copied
- WebM, MKV and others
- What you getMP3 or WAV, re-encoded
- MeasuredPick which under Save as
| File | What you get | Measured |
|---|---|---|
| MP3 | MP3, frames copied | 0:30–1:30 of a 6:44 podcast gave 60.08 s |
| M4A (AAC) | M4A, sound copied | A 3:00 voice memo trimmed in under 0.1 s |
| WAV, 16 or 24-bit | WAV, every sample kept | 1:00–2:00 gave exactly 60.000 s, identical samples |
| FLAC, OGG | The same format, copied | A FLAC stayed FLAC |
| MP4 or MOV video | An M4A of its sound | A screen recording gave an AAC M4A, copied |
| WebM, MKV and others | MP3 or WAV, re-encoded | Pick which under Save as |
How does it find where the sound starts and ends?
It measures the recording’s level every 20 milliseconds as the file loads, then sets the handles at the first and last moments louder than a quiet room, keeping a quarter of a second around them. Check the result by ear: a soft first word can sit below the line.
On a three-minute voice memo it took 2.9 seconds off the start and 17 seconds off the end, where the speaker had stopped and only room noise was left.
Can you trim a voice memo without this page?
On the phone or Mac that recorded it, yes: Voice Memos has its own Trim. On an iPhone, open the memo, tap More, then Edit Recording and the trim button; on a Mac, click Edit, then Trim. Use this page once the memo has been shared, or on another computer.
- 1
Share or save the memo
From Voice Memos, Save to Files on an iPhone, or drag the memo out of the list on a Mac. You get an M4A file.
- 2
Trim it here
It stays an M4A, not re-encoded, so it sounds exactly as it did.
- 3
Send the trimmed file
It’s smaller by whatever you cut, and starts where the talking does.
Is there a faster way to find the part of a long recording you need?
Find it by its words. NoteOwl imports a recording on your Mac and transcribes it with each speaker labelled and a time on every line; tap a line to hear just that moment. Search then finds it again among everything you have recorded.
FAQ
Questions about trimming audio
Is my recording uploaded when I trim it?
No. The audio trimmer reads the file from your device and builds the trimmed copy in the page itself. In our tests the browser made no network requests at all from choosing the file to downloading the result, and there is no account.
How long a recording can the trimmer take?
Up to 2 hours and 1 GB. A 74 MB WAV opened in under a second; the trimmer reads the whole file once to draw its waveform, so an hour-long one takes several seconds. Safari before version 26 reads files whole, and there takes recordings up to 30 minutes.
How precise can the start and end be?
You can type each time to a tenth of a second, nudge it a tenth at a time, or set it to the playhead while listening. A WAV is cut to the exact sample; MP3 and M4A files are cut on their own frames, within about a twentieth of a second.
Can I trim the sound of a video?
Yes. Drop an MP4 or MOV and the trimmer keeps its sound only, as an M4A, without re-encoding when the sound is AAC, as it is in most phone and screen recordings. The picture is left out.
Does it work on a phone?
Yes. Choose the file from your phone’s files, drag the handles with a finger or type the times, and download. On an iPhone, Safari saves the trimmed file to the Downloads folder in the Files app.
Why is the trimmed MP3 a little longer than my selection?
Because an MP3 is made of frames of about 26 milliseconds, and the first frame kept needs the one before it to play correctly. A one-minute selection came out 60.08 seconds long. Choose WAV under Save as when the length must be exact.
Keep exploring
More audio editing tools
- MP3 cutterCut a clip out of an MP3 or any audio file, with fades, or cut a part out of the middle; saves an MP3 at 128, 192 or 320 kbps
- Audio splitterSplit a long recording into parts in your browser: equal parts, every few minutes or where you choose, each split moved to a pause; no re-encoding
- Audio joinerJoin audio files of any format into one MP3 or WAV in your browser, in the order you set, with a pause or a crossfade between them
- MP3 joinerJoin MP3 files into one in your browser, frame by frame with no re-encoding when they match, in the order you set
Related
- M4A to MP3 converterConvert M4A to MP3 in your browser, iPhone and Mac voice memos included, at 128, 192 or 320 kbps; nothing is uploaded
- Online voice recorderRecord your voice in the browser with a level meter, timer and pause, play it back, and save it as MP3 or WAV; nothing is uploaded
- Audio to textTranscription software for your Mac: drop in an audio or video file and get a speaker-labelled transcript with timestamps, unlimited, with nothing uploaded
- Voice memo to textHow to turn a Voice Memos recording into text on a Mac, with Apple’s own tools and with NoteOwl
Recordings you can search, on your Mac
Free to download. Runs entirely on your Mac.
macOS 26 or later · Apple Silicon (M1 or newer) · 16 GB memory minimum, 24 GB recommended
About NoteOwl
NoteOwl is private AI meeting notes and memory for the Mac. It captures meetings without a bot joining the call, labels every speaker, writes summaries and action items, and builds a memory of every conversation that you can chat with — fully offline, because the speech recognition and the AI run on the Mac itself. Dictation into any app is free; Pro is a one-time purchase.
NoteOwl pricing: what’s free and what Pro adds
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