How to use Audio Cropper
- 1Drop in an audio file — it decodes and draws as a waveform
- 2Mark a region, then add another, and another
- 3Choose whether the marked regions are removed or kept
- 4Type exact start and end times to fine-tune any region
- 5Export and download the result
What Audio Cropper does
Editing a recording is rarely one cut. A recorded interview has a false start, a phone ringing twenty minutes in, and a long goodbye at the end — three separate problems that a single-selection trimmer makes you solve in three passes, exporting and reloading between each one.
Working with a list of regions instead changes that. Every section you want gone is marked before anything is processed, and the whole edit is applied once. That also means one re-encode rather than three, which matters because each pass through a lossy format costs quality.
When to use it
- Cleaning up an interview
- False starts, interruptions and the wind-down at the end are marked as separate regions and removed together, leaving one continuous recording.
- Cutting adverts from a recorded broadcast
- Breaks are scattered through the recording rather than contiguous. Marking each one and removing them in a single pass is far quicker than repeated trimming.
- Keeping several highlights
- In keep mode the marked regions are what survive, joined in order. Pulling four quotable moments out of an hour becomes one operation.
- Removing repeated interruptions
- A recording with a recurring noise — a door, a notification, a cough — can have every instance marked and removed at once.
Audio Cropper settings explained
- Remove
- The marked regions are deleted and what remains is joined together in order. The usual mode, since it is easier to mark the few bad parts than the many good ones.
- Keep
- Only the marked regions survive, joined in the order they appear in the recording. Use it when the parts you want are a small share of a long file.
- Multiple regions
- Add as many as you need. Each appears on the waveform and in a list, so you can see the whole edit before committing to it — which is what distinguishes this from the trimmer.
- Exact times
- Each region has From and To fields in seconds. Dragging finds the approximate place; typing sets it precisely, which matters on a long recording where a screen pixel spans several seconds.
- Region list
- Every marked region can be selected, adjusted or deleted individually. Nothing is applied until you export, so regions can be revised freely.
Cropper or trimmer
| Audio cropper | Audio trimmer | |
|---|---|---|
| Sections per pass | Several | One |
| Modes | Remove or keep the marked regions | Keep or remove one selection |
| Preview | Rebuilt from the region list | Instant in keep mode |
| Best for | Cleaning a long recording | Pulling out a single clip |
Limits and what to expect
- Regions cannot overlap; overlapping marks are resolved before processing.
- Cuts land on sample boundaries rather than zero crossings, so a join can click — add fades where it matters.
- Exporting to a lossy format re-encodes, so the result is a second generation unless you choose WAV or FLAC.
- 150 MB per file, and long recordings decode slowly because samples are held uncompressed.
- Regions are not saved; closing the tab discards the whole edit.
Troubleshooting
- There is a click where two sections join
- The cut fell partway through a waveform cycle, so the signal jumps instantly between two levels. Add a short fade at that boundary — a few hundredths of a second is enough to remove the transient without being audible.
- I marked a region in the wrong place
- Select it in the list and adjust its From and To values, or delete it. Nothing is applied until you export, so the region list can be revised as many times as you like.
- Keep mode gave me the wrong parts
- The two modes are inverses: remove deletes what you marked, keep discards everything else. If the result is the opposite of what you wanted, switch the mode rather than re-marking every region.
- I cannot place regions precisely enough
- Type the times into the From and To fields instead of dragging. On an hour-long recording a single screen pixel can represent several seconds, so dragging can never be exact.
Your files and your privacy
The recording is decoded, edited and exported inside your browser tab using your device's own audio engine. Nothing is uploaded at any stage, including during preview playback. Given that the usual reason to cut several sections out of a recording is that those sections should not be heard, keeping the whole operation local is the point.
What to use next
FAQ
How do I remove several parts of a recording at once?
Mark each unwanted section as its own region, leave the mode on remove, and export. Every marked region is deleted in one pass and the remaining audio is joined in order — one operation and one re-encode rather than several.
What is the difference between this and the audio trimmer?
The trimmer works with a single selection, which makes it faster for pulling out one clip. The cropper holds a list of regions, so several separate sections can be removed or kept together. Use the trimmer for one cut and the cropper for cleaning up a recording.
Can I keep several sections instead of removing them?
Yes — switch to keep mode and the marked regions become the output, joined in the order they appear in the source. That is the efficient way to pull a handful of highlights out of a long file.
Why is there a click where the audio joins?
Audio is a continuous wave and cuts almost never land where it crosses zero, so the join is an instantaneous jump between two levels. A fade of a few hundredths of a second removes it without being audible as a fade.
Does cropping reduce quality?
The cut itself only removes samples and loses nothing. Quality is decided by the export format — WAV or FLAC preserve the result exactly, while MP3 or AAC re-encode it. Doing all your cuts in one pass rather than several avoids compounding that.
Is my recording uploaded?
No. Decoding, editing, playback and export all happen in your browser on your own device.