SFX-TrimmerSound effects that start on the first frame.
Drop your SFX: the silence before and after is cut away and collection files are split into single sounds – ready for your timeline.
Drop sound effects here
Files or whole folders · WAV, MP3, M4A, FLAC, OGG and more – even video
Nothing is uploaded – your sounds never leave your computer.
Drop in. Done. Onto the timeline.
No zooming into waveforms, no cutting by hand – SFX-Trimmer does the boring part for you.
Drop your sounds
Drag single files, many files or whole folders onto this page – or into the free app.
Trimmed in seconds
The silence before and after every sound is removed, the natural tail stays. Collection files are split into single sounds.
Onto the timeline
Download the clean WAV files – or let the app save them right next to your originals. Every sound starts on the first frame.
Starts on frame 1
Built for editors who use a lot of sound effects
Made by a video editor who got tired of trimming every whoosh by hand.
Right on the first sound
Finds the exact moment the sound begins – even under background noise – and keeps just 2 ms in front so nothing clicks.
Collections split automatically
Five whooshes in one YouTube download? You get five separate sounds – each collection in its own folder.
Hundreds at once
Drop whole folders, subfolders included. A typical batch is done in a few seconds.
Originals stay untouched
You get trimmed copies – your original files are never changed or overwritten.
All common formats, even video
WAV, MP3, AIFF, FLAC, M4A, OGG, Opus and more – plus the audio of MP4, MOV or MKV files. Output is lossless WAV.
Private by design
Your sounds are processed on your own computer – in the browser and in the app. No account, no upload.
The free app for whole folders
Same trimming as on this page – made for big sound libraries.
- Trims hundreds of sounds at once, folders and subfolders included
- Saves them right next to your originals – in a “Trimmed” folder
- Works offline, on Mac and Windows
Mac
macOS 13 Ventura or later · Apple Silicon & Intel
Signed and notarized by Apple. Open the file and drag SFX-Trimmer into your Applications folder.
Windows
Windows 10 or 11 · 64-bit
No admin rights needed. If Windows shows “Windows protected your PC”, click “More info” → “Run anyway”.
Free · Version 1.0.0
SFX-Trimmer uses code of FFmpeg licensed under the LGPLv2.1 and its source can be downloaded here.
Questions & answers
Are my files uploaded?
No. Everything happens in your browser: your sounds are read, trimmed and saved on your own computer – they never leave it. The app works the same way, even completely offline.
Is SFX-Trimmer really free?
Yes. No trial, no subscription, no account.
Browser or app – what’s the difference?
Both trim with exactly the same engine. The browser version is perfect for a few files right now. The app is faster for whole sound libraries, works offline and saves the trimmed sounds right next to your originals.
Which file formats work?
WAV, MP3, AIFF, FLAC, M4A/AAC, OGG and Opus – plus the audio track of videos such as MP4, MOV or WebM. In the browser, the exact list depends on your browser (Chrome and Edge read the most); the app also reads rarer formats like WMA or AMR. The trimmed sounds are always saved as WAV: lossless and sample-accurate – MP3 or AAC would add silence to the start again.
How does it recognise collection files?
When a file contains several sounds with clear pauses in between – like the whoosh packs you find on YouTube – SFX-Trimmer saves each sound as its own file (“Name 01.wav”, “Name 02.wav” …). If a file should stay in one piece, click “Keep as 1 sound” in the list. You can also turn automatic splitting off in the settings.
Which editing programs does it work with?
With all of them: Premiere Pro, DaVinci Resolve, Final Cut Pro, After Effects, CapCut and any other program that can import WAV files.
Windows says “Windows protected your PC”. Is that safe?
This notice from Microsoft SmartScreen appears for new programs that Microsoft doesn’t know yet. Click “More info” and then “Run anyway”. The installer only installs SFX-Trimmer for your user account and needs no administrator rights.
What do I need?
For the browser version: an up-to-date Chrome, Edge, Firefox or Safari. For the app: macOS 13 Ventura or later (Apple Silicon or Intel), or Windows 10 or 11 (64-bit).
I found a bug or have an idea.
Great – write to support@sfxtrimmer.com. Feedback is very welcome.