Make audio louder: volume booster and normalizer

Boosting the volume simply multiplies every sample by the same amount: +6 dB roughly doubles the signal level. You can do that in Manual mode (−20 to +30 dB). The catch is knowing how much is enough: a quiet phone recording may need +15 dB, an almost-fine song +2 dB.

Normalizing works it out for you. The tool first measures how loud the recording sounds on average, then applies exactly the gain needed to hit the target you choose. That makes several files equally loud: episodes of a podcast, songs in a playlist, lessons in a course. Peak mode is the old-style normalization: it raises the loudest point to −1 dBFS, which doesn't guarantee equal perceived loudness.

LUFS (Loudness Units relative to Full Scale) is the standard measure of perceived loudness, defined in ITU-R BS.1770 and used by EBU R 128 in Europe and ATSC A/85 in the US (where it's called LKFS). It weights frequencies the way the ear does and ignores silent passages. The tool runs this measurement in your browser.

Target	Typical use
−14 LUFS	YouTube, Spotify and other music streaming
−16 LUFS	Podcasts, Apple platforms
−19 LUFS	Speech, audiobooks, voice-over
−23 LUFS	Broadcast TV and radio (EBU R 128)

Streaming services turn loud tracks down to their own reference, so pushing above −14 LUFS rarely makes a song sound louder there.

Raising the gain can push the loudest peaks past the digital maximum (0 dBFS), where they would be cut off and distort. With No distortion (recommended) ticked, a limiter gently turns down just those peaks so they stay under a −1 dBFS ceiling, leaving the rest untouched. The page tells you in advance how far the peaks would go over, and after saving it reports the final loudness, peak level and the maximum reduction the limiter applied.

If the recording is already louder than your target, the tool turns it down instead and tells you so.

Use Original and Processed to compare a 15-second excerpt from the middle of the file before saving. Save as MP3 (128, 192 or 320 kbps) or lossless WAV; the file name gets -louder added.

You can drop a video (MP4, MOV and others) too; its soundtrack is processed and saved as an audio file. The picture isn't included.

• Boosting raises background noise as much as speech. For very quiet recordings with hiss, a noise-reduction step in an audio editor helps before boosting.
• Normalize every episode or song to the same target for a consistent listening experience.
• Keep a copy of the original.

All processing happens in your browser; the file is never uploaded.