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Audio Trimmer

Cut audio on a real waveform — instant lossless WAV or 320k MP3 export. 100% in-browser.

LOCAL · WEB AUDIOReal waveformLoop previewWAV or MP3100% local

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Drop an audio file here, or click to browse

MP3, WAV, M4A, OGG, FLAC (max 100 MB)

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Drop an audio file, drag handles on the waveform, and export WAV or MP3

Data Source & Legal Disclaimer

Effective: 2026Last updated: TodayUpdate: Manual review

Sources: Web Audio API — MDN

Audio trimming runs entirely in your browser using the Web Audio API and ffmpeg.wasm. Your file is never uploaded to any server.

See all data sources & update policy →

Two export paths — illustrated

The waveform you see is computed from the actual decoded samples: the Web Audio API decodes the whole file to PCM, and the tool draws min/max peak pairs per pixel column. Trimming then works on those same samples — the WAV path copies the selected float samples straight into a 16-bit PCM file (44-byte header + interleaved data), which is instant and bit-exact. The MP3 path hands the file to ffmpeg with -ss/-t and re-encodes at 320 kbps — smaller files, one lossy generation added. Decode support depends on your browser: MP3, WAV, and M4A/AAC work everywhere; OGG/FLAC can fail on Safari (convert first).

decodeAudioData → waveform peaks → sample-slice WAV (instant) or ffmpeg MP3

WAV export is a pure memory copy of the selected samples; MP3 export re-encodes for a smaller file.

Cleaning a call recording — Marco's intro cut

Marco records a 45-second voice memo that starts with 2.5 s of fumbling and ends with 2.5 s of table noise.

Read the waveform:The decoded waveform shows flat near-silence at both ends and dense peaks from 0:02.5 to 0:42.5 — exactly the speech
Select:He drags the start handle to 2.5 s and the end handle to 42.5 s: a 40.0 s selection, previewed on loop before exporting
Export WAV:40.0 s × 44,100 samples/s × 2 ch × 2 B = 7,056,000 bytes ≈ 6.7 MB of bit-exact PCM — instant, no encoder
Or export MP3:For email he switches to MP3 320k: ≈ 40 s × 40 KB/s ≈ 1.6 MB — a quarter of the size with speech-quality retention

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About this tool

What is this tool?

Trim audio on a real waveform: lossless WAV or 320k MP3 export. In-browser, free.

Real waveformLoop previewWAV or MP3100% local

What Is the Audio Trimmer?

The Audio Trimmer decodes your audio with the Web Audio API, draws the true waveform, and lets you drag dual handles (with keyboard control) to select a region. Preview loops the selection, then you export: instant bit-exact WAV or ffmpeg-encoded 320k MP3. Everything runs locally.

How to Trim Audio

Drop an audio file and wait a moment while it decodes. Drag the handles to select the segment, press Loop selection to verify, pick WAV or MP3, and export. The result plays inline before you download.

Frequently Asked Questions

What is the difference between the WAV and MP3 export paths?

WAV export slices the already-decoded samples straight into a 16-bit PCM file — instant and bit-exact, since it is a pure memory copy. MP3 export runs the original file through ffmpeg with -ss/-t and re-encodes at 320 kbps — smaller files, with one lossy generation added.

Why does my audio fail to decode?

The Web Audio decoder depends on your browser: MP3, WAV, and M4A/AAC decode everywhere, while OGG and FLAC can fail on Safari. Convert the file to MP3 or WAV first (Audio Converter), then trim it.

Is the waveform real or a mock-up?

It is real. The Web Audio API decodes your entire file to PCM samples, and the canvas draws the min/max peak pair of every pixel column from those samples — the same samples the WAV export later writes out.