How to Trim a Voice Recording on iPhone, Android or Windows (and Split an Hour-Long File)

Pick the method by where the file is

Recordings come from three places: a phone's recorder app, a PC (Sound Recorder, a meeting app, a dictation device), or someone else who sent you the file. If the recording is still on the phone that made it, the phone's own app is the shortest path — no transfer, no conversion. Once the file is on a PC, the choice is between a tool you drag with the mouse and a command that leaves the audio data untouched.

iPhone: trim in Voice Memos

Voice Memos has had a trim tool for years. These steps follow Apple's iPhone User Guide; the icons have moved around between iOS versions, but the yellow handles have stayed the same.

1. 1Open Voice Memos (it lives in the Utilities folder if it isn't on your Home Screen).
2. 2Tap the recording, tap the More button, then open the edit screen.
3. 3Drag the yellow trim handles around the part you want to keep or remove. Pinch open on the waveform to zoom in for precise placement, and tap play to check the selection.
4. 4Tap Trim to keep the selection and drop the rest, or Delete to remove the selection — handy for a cough or an interruption in the middle.
5. 5Tap Apply, then Done.
6. 6Choose Save Recording to overwrite the original, or Save as New Recording to keep the original as it was.

Android: Pixel Recorder and Samsung Voice Recorder

Google Recorder (Pixel 3 and later, Pixel Tablet)

Google's Recorder app can trim by the waveform or by the transcript it generates, which makes it easy to cut a long talk down to the sentences you need. From Google's Pixel help page:

1. 1Open Recorder and tap the recording.
2. 2Tap Menu → Crop & Remove.
3. 3Select the audio or transcript you want to keep and tap Crop — or select what you want to drop and tap Remove.
4. 4Tap Save copy, name the file and tap OK. The original recording stays as it was.

Samsung Voice Recorder (Galaxy)

Samsung's Play Store listing for Voice Recorder says you can manage and edit recorded files in the app. Samsung's own step-by-step page was written for the older Galaxy Note 4, but the flow is the same idea: open the recording, tap the edit (trim) control, move the trimmers to the length you want, listen to the trimmed section, then save — at which point you can replace the file or create a new audio file.

Windows: Sound Recorder records, but it doesn't trim

The Sound Recorder app in Windows 11 records up to three hours per file. Microsoft's FAQ for it covers starting (Ctrl+R), pausing (Space) and stopping (Esc) a recording, then renaming, sharing and deleting it. There is no trim function in that list, so on Windows you need something else for the cut.

The quickest option without installing anything is a browser cutter that decodes the file on your own machine. The steps for the Audio Cutter on this site:

1. 1Open the Audio Cutter page and drop the recording onto it (M4A, MP3, WAV, OGG and FLAC all work).
2. 2Drag across the waveform, or type the start and end times into the fields.
3. 3Press Play selection to check the edges.
4. 4Save. You get a 16-bit WAV of exactly the part you selected.

In my test, a 20-minute M4A (8.1 MB, 48 kHz mono) opened in 0.82 seconds in Chrome, and saving a 2-minute WAV took 61 milliseconds and produced 11,520,044 bytes. WAV is uncompressed, which is why a 2-minute WAV is larger than a 20-minute M4A. If you need a smaller file afterwards, convert it to MP3 or M4A.

FFmpeg: keep the M4A, or split an hour-long file

FFmpeg is a free command-line tool. On Windows, run winget install Gyan.FFmpeg in Command Prompt or PowerShell, then open a new window. With -c copy FFmpeg copies the compressed audio as it is instead of decoding and re-encoding it, so the cut has exactly the quality of the original and runs almost instantly.

ffmpeg -ss 30:00 -to 32:00 -i meeting.m4a -c copy decision.m4a

I made a 60-minute test recording (AAC, 48 kHz mono, 25.0 MB) and cut the same 2 minutes three ways. The stream copy took 0.09 seconds and came out at 836,737 bytes. Re-encoding to AAC at 64 kbps took 1.04 seconds and ended up almost the same size. Saving those 2 minutes as WAV gave 11,520,078 bytes — 13.8 times the M4A.

Split a long recording into 10-minute pieces

ffmpeg -i meeting.m4a -f segment -segment_time 600 -reset_timestamps 1 -c copy part_%02d.m4a

On the 60-minute file this finished in 0.64 seconds and wrote six 10-minute files of about 4.17 MB each. It also wrote a seventh file of 943 bytes holding 0.02 seconds of audio, because the recording was exactly 60:00 long. If you see a tiny last piece like that, delete it.

Cut the first 10 seconds off every recording in a folder

New-Item -ItemType Directory -Force trimmed | Out-Null
Get-ChildItem *.m4a | ForEach-Object {
  ffmpeg -ss 10 -i $_.FullName -c copy (Join-Path trimmed $_.Name)
}

Run it inside the folder with the recordings. The trimmed copies go into a trimmed subfolder and the originals are left alone. On two 10-minute test files, both came out at 9:50.

Before you send a trimmed recording to anyone

• Check where the file goes. Many online audio editors upload the file to their server before cutting it. A meeting or a phone call has other people's voices in it; tools that run on your own device avoid that question entirely.
• Keep the original until you've listened to the cut. Save as New Recording on iPhone and Save copy on Pixel do this for you.
• Listen to both edges. Cuts that land mid-word are the most common reason to redo a trim. Leaving half a second of room at each end is usually enough.

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