Let’s Talk
Audio/Video / Tool 29 / FREE TO USE

Audio Trimmer & Converter

Trim locally decoded audio and export WAV, Opus OGG or browser-supported M4A. MP3 export is unavailable.

Use the tool ↓Read the field guide ↗
THE WORKBENCH

Keep the sound that matters.

IN YOUR BROWSER / PRIVATE INPUT
YOUR PRIVATE WORKSPACE

Keep the part worth hearing.

100% in your browser, files never leave your device.

Choose, drop or paste audioBATCH UPLOAD

30 MB source, five minutes maximum; export a selection up to two minutes.

Audio output
Audio bitrate (kbps)

MP3, WAV, OGG and M4A input depend on browser decoding. MP3 output is unavailable: common MP3 encoders conflict with this project’s permissive-only licensing rule. WAV is lossless PCM; its bitrate is determined by sample rate and channels. OGG uses Opus, not Vorbis. M4A is encoded in real time when supported.

Native recording runs near playback speed. Keep this tab visible. Encoders vary by browser; unsupported codecs fail clearly. Compression may increase file size. Cancel discards the new copy.

01 / FROM INPUT TO ACTION

How to use the
Audio Trimmer & Converter

  1. 01

    Choose the task

    Select the relevant mode in the Audio Trimmer & Converter workspace. The controls describe the accepted input and output.

  2. 02

    Choose and listen

    Open a local audio file and use the source player to find the useful section. MP3, WAV, OGG and M4A inputs work when the browser decodes their codecs.

  3. 03

    Mark the selection

    Enter start/end times in seconds or use the preview position. Choose up to two minutes from a source no longer than five minutes.

02A CLOSER LOOK

Choose an audio format for the next step

WAV is not made smaller by the compressed-audio bitrate control. Its rate follows sample rate, channels and bit depth. Exporting MP3 to WAV does not restore discarded detail: it stores the decoded approximation in an uncompressed container.

MP3 output is unavailable. Common browser MP3 encoders and FFmpeg builds conflict with this project’s permissive-only dependency requirement. Input support is separate from output support; this tool never labels WAV or Opus bytes as MP3.

OutputContentsBest fit
WAV48 kHz, 16-bit PCM, mono or stereoEditing and precise sample-range export
OGGOpus through WebCodecsSmall listening copies where Opus is supported
M4ANative browser AAC recording, if availablePlayers that accept AAC/M4A
03THE MATH, EXPLAINED

What trimming and mono mixing actually do

WAV bytes ≈ 44 + seconds × 48,000 × channels × 2

The source is decoded locally and resampled to 48 kHz. Start and end times become sample indices. Mono output averages source channels; stereo output keeps the first two channels. Surround mixing is not performed.

A ten-second stereo WAV is roughly 1.92 MB. A compressed copy can be much smaller, but lossy encoding may introduce artifacts. Bitrate affects Opus and M4A rather than PCM. Sources are capped at 30 MB and five minutes to reduce decoded-memory pressure. Metadata is checked before full audio decoding.

04IN PRACTICE

Extract a clean section from an interview

Listen around both boundaries. Cutting in the middle of a word or waveform can sound abrupt; this tool does not apply automatic fades or remove background noise. Keep a lossless master when you expect to edit again.

WAV follows the decoded sample range. Native recording and codec priming can slightly change compressed boundaries; use WAV when precise trimming matters. M4A runs near real time, so keep the tab visible until it completes.

THE STARTING POINT
Interview source
Start 12.50 s, end 32.50 s
Mono, Opus 96 kbps
THE RESULT / NEXT STEP
20-second listening copy
One mixed channel
Measured size and playback after export
Review the actual encoded file rather than an estimated compression ratio.
05UNDERSTAND THE RESULT

Avoid common audio conversion mistakes

01

Choose bitrate deliberately

Higher bitrate cannot recover detail already lost in a source. Compare with headphones before replacing anything.

02

Check mono compatibility

Averaging channels can cancel out-of-phase material. Preview music and stereo effects carefully.

03

Check browser codec capabilities

Opus requires AudioEncoder/WebCodecs. M4A requires a compatible MediaRecorder. WAV is the fallback when compressed encoding is unavailable.

04

Keep the original

Cover art, chapters and source metadata are not transferred. Cancel discards the unfinished local copy.

THE QUESTIONS THAT COME NEXT

Audio Trimmer & Converter:
questions, answered.

Can I convert MP3 to WAV without uploading it?

Yes, when the browser decodes the MP3. The selection is written locally as 48 kHz 16-bit PCM WAV; lost source detail is not restored.

Does this audio converter export MP3 files?

No. MP3 encoding is unavailable under the dependency licensing constraints. Choose WAV, Opus OGG or an available native M4A encoder.

Is this OGG output Vorbis or Opus?

It is Opus inside OGG. Some older players expect Vorbis from an .ogg file, so verify your target player or choose WAV.

Why does an M4A trim have a small timing difference?

Native recording and AAC priming can slightly shift boundaries. Export WAV for precise sample-range trimming and inspect the result.

FURTHER READING

The calculations and checks above describe this tool's implementation. Use these primary references for the underlying formats and publishing guidance.

Browser recording and supported formats ↗ (opens in a new tab)MediaStream recording specification ↗ (opens in a new tab)
A USEFUL NEXT STEP

Keep the
work moving.

30

Video Compressor & Converter

Resize a clip while retaining or removing its audio.

↗28

Video to GIF / GIF Maker

Turn visual motion into a silent loop.

↗10

Word Counter & Text Analyzer

Count words in a prepared transcript.

↗
YOUR NEXT MOVE

Put Audio Trimmer & Converter to work.

Trim locally decoded audio and export WAV, Opus OGG or browser-supported M4A. MP3 export is unavailable.

Use the Audio Trimmer & Converter↑
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