Normalize volume
Even out loudness with FFmpeg loudnorm, in the browser.
Runs in this tab. The file stays here.
This runs in your browser. Nothing is uploaded. Longer clips take longer here than they would on a fast server. That's the trade-off for not sending the file.
About Normalize volume
Evens out loudness of an audio file in your browser with FFmpeg’s loudnorm filter, without sending the recording to a loudness app.
One speaker close to the mic, one far away, a podcast that makes you grab the volume knob every thirty seconds, loudnorm is the usual FFmpeg fix. This page runs a single-pass `-af loudnorm` and writes MP3. Two-pass loudnorm is more accurate and twice as slow; I didn't put a progress bar on two full encodes for a filter most people won't A/B.
This isn't a limiter for club masters and not a “make it broadcast legal” suite. It pulls the integrated loudness toward a sane spoken-word range. If the file is already even, you may not hear a change. If it's a disaster, you will.
I'm not going to print a BMI-style health warning on a volume tool. It changes levels. It doesn't master your album. Check the result on headphones you trust.
How to use Normalize volume
- 1Drop the uneven recording.
- 2Click Normalize and wait. The filter isn't instant.
- 3Download and listen before you ship it.
What it won't do
- Single-pass loudnorm, MP3 out.
- No LUFS number field.
Common questions
What loudness target does this use?
FFmpeg’s loudnorm defaults, not a custom LUFS box. If you need −16 LUFS exactly, a desktop loudness meter is the right instrument. This page is “make the quiet parts less quiet” for spoken-word messes, not a broadcast-legal suite with a printed target.
Why is this a single pass?
Two-pass loudnorm measures then applies. That's two encodes in wasm. Single pass is what I'll stand behind for a browser tab. The result is still better than the source on uneven podcasts, even if a desktop meter would quibble about the exact integrated LUFS.
Will normalize clip the loud parts?
Loudnorm tries not to. It isn't a brickwall. If the source is already slammed into 0 dBFS, you won't get a miracle, you will get a different kind of mess. Listen on headphones you trust before you publish.
Related tools
Why this one doesn't upload your file
There is no server to upload to. This page is a static file, and the work happens in your browser using the same graphics and WebAssembly code that renders every other site you visit. Your file is read from disk into memory, processed, and handed back as a download. Once the page has loaded you can disconnect from the network entirely and it keeps working. The longer explanation