How to Trim and Split Audio in Your Browser
Follow StemNook screenshots to trim a chosen audio section, preview it, download a WAV and split a recording into timed parts, with clear file and device limits.
The short answer: Open the audio cutter, choose an MP3 or WAV, enter start and end times, preview the selection and create a clip. To make several regular parts, enter a clip length and split the whole file. Download each result as WAV.
You have a recording with one useful answer in the middle. Sending the entire recording makes the listener search for it. A short clip is easier to review, repeat or share.
My first decision would be simple: do I need one passage, or several regular pieces? In StemNook, those are two controls in the same browser editor. Choosing the right one avoids a lot of unnecessary cutting.
This tutorial uses a seven-second synthetic spoken demo recording for its timing examples. It is a demonstration recording, not a customer recording, song-quality comparison or claim that an AI model separated singing perfectly.
For this walkthrough, I kept the 1–3 second interval and checked the downloaded WAV: it was two seconds long. I then split the full seven seconds into 3-, 3- and 1-second files. Those are local editing checks, not AI separation results. The screenshots show the controls used for each step.
Download the seven-second spoken demo WAV to follow the screenshots, or use your own recording.
1. Choose between trimming and timed splitting
Use Create clip when you know the beginning and end of one passage. The result is one file containing that selected interval.
Use Split file when you want the whole recording divided into regular lengths. The last part can be shorter. This operation does not find the end of a sentence, identify a speaker or detect silence.
| Your task | Control | Example |
|---|---|---|
| Keep one answer | Start, end and Create clip | Keep seconds 1 through 3 |
| Review a recording in order | Clip length and Split file | Seven seconds becomes 3 + 3 + 1 |
| Remove music from a voice | Homepage AI separation | A different cloud workflow |
Open the audio cutter. The browser processes this editing operation locally. You do not need to upload this audio to a processing server or sign in to use the cutter.
Local audio processing is a statement about this tool’s file handling. It is not a claim that the entire website has no network activity, and it does not apply to the homepage AI separator.
2. Open a file that your device can handle
Choose a valid MP3 or WAV. The editor accepts files up to the displayed 30 MB limit and 10 minutes in duration.
There is also a decoded-audio memory limit. A compressed file can be small on disk but become much larger when the browser opens it. The ten-minute limit therefore does not guarantee that every ten-minute file will open on every device.
If a phone struggles, start with a shorter file or try a desktop browser. Do not assume a file is damaged merely because one device runs out of working memory.
After opening the recording, check its file name, duration and channel information. Our walkthrough uses a seven-second, mono recording. Your own recording can have different values; keep your timing decisions within the duration the editor shows.
You will see a waveform and time controls. Treat the waveform as a map of changing loudness, not a transcript. It cannot tell you which sentence or lyric is present at a particular position.
3. Enter the start and end of the passage
For the example, enter 1 in Start (seconds) and 3 in End (seconds). That means keep the interval beginning at one second and ending at three seconds.
The resulting length is 3 − 1 = 2 seconds. The end time is a position inside the original, not the number of seconds you want to keep.
You can adjust the corresponding start and end sliders too. This tutorial does not rely on dragging a selection directly across the waveform.
The editor accepts decimal-second positions. Use them when a word starts between whole seconds, but listen to the boundary before deciding that a particular decimal is the right cut.
The start must be earlier than the end, and both must be inside the source duration. If the interval is invalid, correct the values rather than repeatedly clicking Create clip.
4. Preview both edges before you create the clip
Use Preview selection. Listen for the first word, the last word and anything that slips in just beyond the passage you intended.
A useful clip often needs a small amount of room around speech. Cutting exactly at the loudest syllable can remove the beginning of a word. Moving the end too close can make a sentence feel unfinished.
For a music excerpt, listen for the beat and the tail of an instrument as well. A convenient visual point on the waveform is not automatically a smooth musical boundary.
This cutter does not provide automatic fades, silence detection or guaranteed click-free editing. You decide where to cut. If the recording requires a shaped fade or more detailed repair, finish that part in an editor that offers those controls.
When you change the interval, any previously prepared clip list is cleared. That helps avoid downloading a file made from old timing values. Check the final numbers and create the clip again.
5. Create the clip and download the actual WAV
Use Create clip. A result row lists the interval you selected and offers Download clip 1.
That row represents a prepared export. Use its download button to save the WAV to your device. Do not assume that selecting the interval already saved a file.
For the example, the file name ends in -clip-1.wav. The output is 16-bit PCM WAV, and its sample rate follows the browser-decoded audio. This is why you should not promise a fixed output sample rate for every browser or file.
Open the downloaded WAV in your usual player. Check that it is about two seconds long and listen to the first and last sounds again. The downloaded artifact is the final check; the in-page preview is a useful earlier step.
WAV export is not the same as keeping the original MP3 bytes. An MP3 input still produces WAV, and changing the extension afterwards will not convert it into an MP3.
6. Split the full recording into regular parts
If you want several clips, go to Need several clips? and enter 3 in Clip length (seconds). Then use Split file.
For a seven-second original, the editor prepares these intervals:
| Part | Interval | Length |
|---|---|---|
| 1 | 0–3 seconds | 3 seconds |
| 2 | 3–6 seconds | 3 seconds |
| 3 | 6–7 seconds | 1 second |
The regular splitting operation uses the whole source, not only the earlier 1–3 second selection. The last file is shorter because only one second remains.
Download each part separately. The current tool does not package the parts into a ZIP. If you need to preserve their order outside the browser, keep the numbered names or label them in your own folder.
There is a maximum of 60 clips. If the chosen length would produce more, use a longer duration per part. This limit is about the number of exports, not a promise that every device can process the largest possible job.
Timed splitting can cut through a word or a beat. For a single complete sentence, go back to start and end times instead.
7. Check these three problems before trying again
The file will not open
Check MP3/WAV, size and duration. A corrupt recording, an unsupported decoding path or too much decoded memory can prevent opening. Try a shorter valid file before deciding which issue you have.
The selection is rejected
Look at both times. A start of 5 and an end of 3 cannot produce a forward interval. The error screenshot shows that invalid selection; correcting the values is the next action.
The exported file is unexpectedly large
PCM WAV is larger than many MP3 inputs. Format, duration, sample rate and channel count affect the size. A shorter export reduces the amount of audio, but this cutter is not a dedicated compression tool.
Keep one useful passage first
Start with a small recording you are allowed to edit. Select one interval, preview it, create the clip and check the downloaded file. Once that feels familiar, try regular parts.
For voice and music separation, use the homepage workflow. For more context, the audio file splitter explains timed parts, while the stems explainer covers a different meaning of “split.”