Audio Trimmer
Trim and cut audio files to remove unwanted sections. Precise editing for MP3, WAV & other formats. Extract clips or shorten recordings instantly.
About Audio Trimmer
Free Online Tool
Audio Trimmer
Drag the start and end sliders to select exactly the section you want to keep, preview it, and download the trimmed audio — no timeline editor, no learning curve.
How to Use This Tool (30 Seconds)
- 1Upload Your Audio File: Click the upload zone and select your file. MP3, WAV, OGG, FLAC, and M4A formats are all supported. The waveform renders automatically after upload.
- 2Set the Start Point: Drag the left slider to the position where you want the trimmed audio to begin. The timestamp updates in real time as you drag.
- 3Set the End Point: Drag the right slider to your desired end position. The highlighted region between both sliders shows exactly what will be kept in the output.
- 4Preview the Selection: Hit 'Play Selection' to hear only the region between your two sliders before committing. Adjust either handle until the cut sounds clean.
- 5Download the Trimmed File: Click 'Trim & Download.' Only the selected region is exported — everything outside the sliders is permanently removed from the output file.
How Slider-Based Audio Trimming Works
Each slider maps its pixel position to an exact audio timestamp using the audio file's total duration. The tool uses the Web Audio API's AudioBuffer to read and write raw audio sample data within the selected range:
// Map slider position to timestamp
timestamp = (sliderPosition / sliderWidth) × audioDuration
// Convert timestamps to sample indices
startSample = startTime × sampleRate
endSample = endTime × sampleRate
// Copy only selected samples into new buffer
trimmedBuffer = audioCtx.createBuffer(channels, endSample − startSample, sampleRate)
trimmedBuffer.copyToChannel(sourceBuffer.getChannelData(0).slice(startSample, endSample), 0)
The sample rate — typically 44,100 Hz for MP3 and 48,000 Hz for WAV — defines how many individual data points exist per second of audio. A precise trim at 44,100 Hz means the cut is accurate to 1/44,100th of a second — far beyond what the human ear can detect as an abrupt or misaligned cut.
Input Format Support & Best Use Cases
| Format | Compression | Typical Sample Rate | Best For Trimming |
|---|---|---|---|
| MP3 | Lossy | 44,100 Hz | Podcasts, music clips, voice notes |
| WAV | Lossless | 44,100 / 48,000 Hz | Studio audio, voiceover, high-fidelity cuts |
| FLAC | Lossless | 44,100 / 96,000 Hz | Archival audio, master recordings |
| OGG | Lossy | 44,100 Hz | Web audio, game audio assets |
| M4A | Lossy (AAC) | 44,100 Hz | iPhone voice memos, iTunes recordings |
Lossless formats (WAV, FLAC) produce the cleanest trim output since no re-encoding artifacts compound on top of existing compression. For lossy formats like MP3, trim quality is still excellent — the output matches the source bitrate.
⚡ Pro Tip
Always set your trim points on a moment of silence or low audio activity, not mid-word or mid-note. Even a technically perfect sample-accurate cut sounds abrupt if it starts or ends in the middle of a sound wave cycle. Look at the waveform — narrow, flat areas between words or musical phrases are ideal cut points. For a completely seamless exit, position the end slider just after the natural decay of the last sound fades to near-zero amplitude. This removes the need for any fade-out effect and produces a clean, professional-sounding trim every time.
Frequently Asked Questions
Q: How precise are the slider trim points?
Trim accuracy depends on the audio file's sample rate. At 44,100 Hz — the standard for MP3 — cuts are precise to 0.023 milliseconds. In practice, this is imperceptibly accurate. The slider snaps to the nearest sample boundary, so there is no risk of a cut landing mid-sample and creating a click or pop artifact.
Q: Will trimming an MP3 reduce its audio quality?
Trimming a lossy file like MP3 requires re-encoding the output, which introduces a small additional quality loss on top of the original compression. To minimize this, always trim from the highest-quality source file available. If you have a WAV or FLAC version, trim that and convert to MP3 afterward.
Q: Can I trim silence from the beginning and end of a recording?
Yes — this is one of the most common uses. Zoom into the waveform near the start of the file and drag the left slider to just before the first audio activity. Do the same at the tail end. This removes dead air before and after speech without affecting the core recording.
Q: What happens if both sliders are placed at the same position?
The selected region collapses to zero duration and the tool will prompt you to widen the selection before exporting. A minimum selection width of 0.1 seconds is enforced to prevent zero-length file exports.
Q: Can I make multiple cuts from the same file?
This tool extracts one continuous region per export — the section between the two sliders. For multiple non-contiguous clips from the same file, trim and download each section separately by repositioning the sliders between exports without re-uploading.
Q: Why does my trimmed audio have a click or pop at the cut point?
A click at a trim point means the cut landed at a non-zero amplitude — the audio waveform was interrupted mid-cycle. Reposition the slider to a quieter point in the waveform where the amplitude is near zero. You can also enable the fade-in or fade-out option to smoothly ramp the audio up or down over the first and last few milliseconds of the trimmed region.
Q: Is there a maximum file size or duration limit?
Files up to 200MB are supported. For very long recordings — interviews, full lectures, multi-hour sessions — consider splitting the file into segments using a desktop tool first, then trimming individual segments here for precise cuts without browser memory constraints.