Free Online Volume Booster

Boost the volume of quiet audio, MP3 songs and MP4 videos up to 400% directly in your browser. Features speech clarity, anti-clipping limiter, and live mic amplification. 100% private & client-side.

Beta: this tool works for common files but is still being improved; see Limitations below.

About Volume Booster

Volume Booster amplifies quiet audio and video files up to 400% (+12 dB) directly in your browser. Features six instant presets, a precision slider, Speech Clarity mode to sharpen dialogue, and a soft-knee dynamic peak limiter to eliminate harsh clipping.

How to use Volume Booster

  1. Add an audio or video file, or enable Live Mic Amp mode for microphone monitoring.
  2. Choose a preset like Medium (150%) or Double (200%), or drag the volume slider up to 400%.
  3. Enable Speech Clarity to filter out low rumble and sharpen speech formants in dialogues or podcasts.
  4. Switch between Original (Bypass) and Boosted during playback to check loudness and clarity.
  5. Click Export Boosted Audio (WAV) to download the processed audio rendered offline at full fidelity.

When it helps

Quiet video recordings

Phone or camera videos recorded from a distance often have faint audio. Boosting to 150%–200% makes conversations easily audible.

Muffled podcasts or lectures

Combining the volume boost with Speech Clarity cuts HVAC hum and elevates dialogue clarity for effortless listening.

Live microphone boosting

Enhances faint microphone inputs with low-latency amplification for live practice or quick testing with headphones.

Tips

Limitations

What happens to your files

All decoding, processing, and offline audio rendering occur 100% inside your browser using the Web Audio API. Audio files are never transmitted to any external server.

Related guides

Make Quiet Audio Louder Up to 400%

Amplify quiet audio and video recordings with smooth gain controls ranging from 100% to 400% (+12 dB). Choose from six instant presets (Normal, Gentle, Medium, Double, High, and Max) or fine-tune with the smooth slider. Toggle the A/B comparison button at any time during playback to instantly hear the difference between the original and boosted audio.

Speech Clarity & Dynamic Anti-Clip Limiter

Activate Speech Clarity mode to filter out background HVAC rumble under 85 Hz while boosting vocal presence formants around 2.5 kHz, ensuring dialogues and podcast speech remain crisp and intelligible. The integrated soft-knee dynamic peak limiter holds transients safely under -1 dBFS, protecting your speakers and earphones from harsh digital clipping.

Video Synchronization, Live Mic Amp & Lossless Export

Load MP4, WebM, and MOV videos to boost their audio in perfect sync with video playback, or activate Live Mic Amp for low-latency microphone monitoring. When you are ready, export the boosted audio as a 16-bit PCM WAV file rendered offline at full fidelity. Everything runs client-side in your browser with zero server uploads.

Frequently asked questions

How does the online volume booster make audio louder?
The tool uses the browser Web Audio API to apply high-precision digital gain directly to your audio or video file. You can boost volume up to 400% (+12 dB) with presets or a smooth slider, and hear the difference live.
Will boosting volume cause crackling or audio distortion?
Amplifying quiet audio by 200%–400% can push signal peaks beyond digital full scale. Our built-in Soft Peak Limiter dynamically compresses peak transients below -1 dBFS, preserving loudness without harsh clipping distortion.
What does Speech Clarity mode do?
Speech Clarity filters out low HVAC hum and desk rumbles below 85 Hz, and boosts dialogue frequencies around 2.5 kHz. This makes quiet voices and spoken words crisp and clear without needing excessive total volume.
Can this booster increase my computer or phone's master speaker volume?
Browser security sandboxes prevent websites from modifying your operating system's global volume or boosting external apps like Spotify or Netflix. It amplifies audio loaded inside this webpage. For system-wide boosting, use tools like Equalizer APO (Windows) or BlackHole (macOS).
Is it safe and private to boost my audio files?
Yes. All processing, audio decoding, and offline WAV rendering happen 100% inside your device's browser memory. Your files are never uploaded to any server.

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