Top-end reduction
Free Online Low-Pass Filter
Apply a low-pass filter to reduce upper frequencies, soften harshness, and create muted or lo-fi textures. Set the cutoff frequency, preview the result, and export locally in the browser.
Useful for private sound design, voice tests, and music drafts because the original file stays on your device.
Uses FFmpeg low-pass filtering to roll off everything above a chosen cutoff frequency.
A quick way to create darker, softer, or more distant sounding audio without opening a larger editor.
Drag & drop audio here, or click to upload
Supports MP3, WAV, M4A, FLAC, OGG, AAC, and more
How to use the Low-Pass Filter online
- 1.Upload an audio file and let the browser read its duration and sample rate.
- 2.Choose the cutoff frequency that matches how dark, muted, or distant you want the file to sound.
- 3.Choose MP3 or WAV export, process the file in the browser, preview the result, and download it.
Why use this Low-Pass Filter?
Good for lo-fi and distance effects
A low-pass filter is useful when you want a darker tone, softer highs, or an off-screen style sound quickly.
Private browser workflow
FFmpeg runs locally on your device, so source files stay off external servers during processing.
Flexible output
Export MP3 for quick sharing or WAV if you want to keep editing the result afterward.
Common use cases
- •Create a lo-fi or distant voice effect for video and game work.
- •Soften harsh ambience and bright sound effects in a rough mix.
- •Darken a music bed so dialogue can sit on top more easily.
- •Reduce upper-frequency distractions in reference audio.
Tips for better results
- •Cutoffs above about 5 kHz are usually gentler, while lower settings sound much more obvious.
- •If you only need to soften brightness slightly, a treble cut may be subtler than a strong low-pass filter.
- •Preview carefully on speech, because low cutoffs can remove consonant clarity fast.
Low-Pass Filter FAQ
Is this the same as turning down treble?
Both darken the sound, but a low-pass filter removes content above a cutoff more decisively than a simple treble reduction.
Is my audio uploaded to a server?
No. The processing happens in your browser, so the source file stays on your device.
Which formats can I upload?
Most common browser-decodable formats are supported, including MP3, WAV, M4A, FLAC, OGG, and many AAC-based files.
When should I export WAV instead of MP3?
Choose WAV if you plan to keep editing or chain more processing afterward. MP3 is better for quick sharing and review.