Audio Trimmer
Trim mp3, aac, ogg, opus, wav, and flac audio in your browser with ffmpeg.wasm. Drag the waveform thumbs to set start and end, add optional fade-in / fade-out, and keep the source format. No upload, no signup.
Interactive tool
ffmpeg.wasm engine loads on first run (~32 MB)
The engine is cached for the rest of your session. Every transcode runs entirely in your browser: files never leave your device.
Threading: detecting…
Drop an audio file here
Up to 250 MB / 5 minutes. The file never leaves your browser.
What is the Audio Trimmer?
A free, in-browser audio trimmer that supports fade-in / fade-out, runs through ffmpeg.wasm, and keeps the source format by default. Drag the waveform thumbs to set start and end, then export. No upload, no signup.
How to Use the Audio Trimmer
- 1Drop an audio file (mp3, aac, ogg, opus, wav, flac)
- 2Drag the start / end thumbs on the waveform to your cut points
- 3Add an optional fade-in / fade-out (seconds)
- 4Pick the output format (or keep the source)
- 5Click Trim: preview and download
Key features
Waveform-driven scrubber
Visual amplitude envelope makes silence and beats obvious
Numeric inputs as a backup
Type start, end, or duration directly in mm:ss.cs format
Optional fade-in / fade-out
Independent fade durations applied via the afade filter
Six output formats
mp3 / aac / ogg / opus / wav / flac, or just keep the source
Bitrate slider for lossy targets
Pick 24-320 kbps for mp3 / aac / ogg / opus (ignored for wav / flac)
Multi-threaded ffmpeg.wasm
Uses SharedArrayBuffer where available for faster encodes
100% private
No upload, no signup, no logs: the audio stays in your browser
Why Trim Audio Locally?
Cloud trimmers upload your file, often watermark, rate-limit, or run ads. Trimming locally is private, fast, and watermark-free, and you get fade controls and format selection that most free sites don’t expose.
Common use cases
- Cut a 30-second ringtone from a song
- Trim leading silence from a voice memo
- Build a short intro for a podcast with fade-in/out
- Snip a sound effect from a longer recording
- Pre-cut a long interview before importing to your editor
Fade-in / fade-out
Fades are applied via ffmpeg's afade filter. The fade-in starts at 0 and lasts the configured duration. The fade-out is anchored at (trim duration − fade-out duration) so it always reaches silence on the last sample.
Keep source vs explicit format
When "Keep source" is selected the tool re-encodes back to the same container family with the same defaults. Use an explicit target when you want to switch codecs at the same time (e.g. flac → mp3 256 kbps).
Tips & best practices
Add a 1-2 s fade-in to remove pops
When trimming inside a sustained note or word, a short fade-in eliminates the click that comes from cutting mid-cycle.
Trim first, then compress
Use the Audio Converter afterwards if you want to switch format or lower bitrate further. Trimming first always saves the most bytes.
Use opus 64-96 kbps for voice cuts
For voice / podcast trims, exporting to opus is transparent at 64-96 kbps and produces dramatically smaller files than mp3.
Privacy & security
Trimming runs entirely in ffmpeg.wasm inside your browser. The source audio is never uploaded, logged, or stored. Engine artefacts are served from our own origin (not a third-party CDN).
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Generate white, pink, brown, blue, or violet noise in your browser: up to 30 minutes. Pick a duration, sample rate, channels, and loudness; export as wav, mp3, aac, ogg, or opus. Perfect for sleep, focus, ASMR, UGC voice-over beds, and tinnitus masking. No upload, no signup.
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Frequently Asked Questions
Which formats are supported?
Input: mp3, aac, m4a, ogg, opus, wav, flac (plus anything ffmpeg.wasm can decode). Output: same as input ("keep source") or any of mp3 / aac / ogg / opus / wav / flac.
How do the fades work?
Fades use ffmpeg’s afade filter. The fade-in starts at 0 and lasts the duration you set. The fade-out is anchored at (trim duration − fade-out seconds) so it always reaches silence on the last sample.
Does my file get uploaded?
No. Trimming runs entirely in your browser through ffmpeg.wasm. The engine artefacts are served from the same origin under /ffmpeg/<version>/.
Will the trimmed file lose quality?
It depends on the output format. Keeping the source format re-encodes (so there is one generation of lossy re-encode). Choose wav or flac to keep the output lossless.