Lecture & Meeting Audio Enhancer
Clean up lecture recordings, online class audio, and meeting replays. Remove AC noise and echo. Free browser-only audio enhancer.
Drop an audio file here
or click to browse
Supports MP3, WAV, M4A, OGG, FLAC, AAC · Max 500 MB
Enhancement Mode
Lecture recordings and online meeting replays share a common set of problems: air conditioning hum at 60 or 120 Hz, projector fan noise, hard-surface room echo, and the uneven levels that result from multiple participants joining from different devices. Light mode addresses these with minimal processing: a gentle high-pass at 100 Hz removes the HVAC signature without touching the fundamental frequencies of the human voice, and a low-strength FFT denoising pass reduces stationary broadband noise without introducing processing artifacts. The goal is transparency — students and viewers should hear cleaner audio without noticing that it was processed. Output quality is preserved as uncompressed WAV, making it suitable for archiving, transcription with tools like Whisper or Otter.ai, or re-uploading to LMS platforms such as Moodle, Canvas, or Google Classroom.
Free Online Audio Noise Remover — No Upload Required
Zolkit's Audio Enhancer runs FFmpeg's professional audio filters directly in your browser using WebAssembly. Upload any audio file — MP3, WAV, M4A, OGG, FLAC, or AAC — and get clean, broadcast-ready sound in seconds. All processing happens locally on your device; your audio is never sent to any server. No subscription, no account, no Adobe Podcast paywall.
100% Private
Audio never leaves your device. Processing runs entirely in the browser via WebAssembly — no uploads, ever.
FFmpeg-Powered
Uses the same audio filters trusted by broadcasters: afftdn FFT denoising and anlmdn spectral cleanup.
Three Enhancement Modes
Light, Studio, and Rescue modes cover everything from minor hiss removal to heavy outdoor noise.
Fast Local Processing
WASM runs at near-native speed. A 5-minute recording typically processes in under 15 seconds.
Free, No Account
No subscription or sign-up required. Zolkit's Audio Enhancer is free to use with no limits.
Voice Boosted
Studio mode applies dynamic compression to lift vocal presence and even out quiet and loud passages.
How to Remove Background Noise from Audio
- 1
Upload your audio file — drag it onto the page or click to browse. Supports MP3, WAV, M4A, OGG, FLAC, and AAC.
- 2
Choose an enhancement mode: Light for minor noise, Studio for voice and podcasts, or Rescue for heavily noisy recordings.
- 3
Click Enhance Audio. Preview the result with the built-in player, then download the cleaned WAV file.
Frequently Asked Questions
What does Light mode do to a lecture recording?
Light mode applies a 100 Hz high-pass filter to remove low-frequency hum from projectors and air conditioning, followed by gentle FFT denoising at -30 dB — enough to reduce steady background noise without audibly changing the speaker's voice or introducing artifacts.
Can it improve Zoom class recordings?
Yes. Zoom lecture recordings often have inconsistent levels when multiple participants speak and background noise from home environments. Light mode's gentle denoising cleans up the steady-state noise and the high-pass removes desk vibration and HVAC rumble that Zoom's own processing may leave behind.
Is the output suitable for automatic transcription?
Yes. Cleaner audio significantly improves accuracy for automatic transcription services such as Whisper, Otter.ai, and Google Speech-to-Text. The 100 Hz high-pass filter specifically helps, as low-frequency rumble can confuse speech recognizers. Output as WAV at the original sample rate preserves maximum detail.
Should I use Light or Studio mode for an in-person lecture?
Use Light mode if the lecture was recorded in a reasonably quiet room with a decent microphone. The lighter processing avoids over-correcting clean audio. Use Studio mode if the room had noticeable HVAC noise, echo, or if the microphone was far from the speaker — the stronger denoising and dynamic compression will make a bigger difference.