Free Audio Normalizer Online
Normalize audio volume to a target peak level and boost or cut volume — entirely in your browser. Shows before and after dBFS levels for every file. No upload, no account, no file size limit.
Drop audio files here to normalize
MP3, WAV, M4A, AAC, OGG, FLAC · No file size limit
−1 dBFS
Maximum loudness · broadcast / podcast
−6 dBFS
Streaming headroom · good for playlists
−14 dBFS
Approx. −14 LUFS · YouTube / Spotify target
How to normalize audio volume
- 1
Drop your audio files
Drag MP3, WAV, M4A, FLAC, OGG, or AAC files into the upload area — or click to select them. Files stay on your device.
- 2
Set target peak level
Choose the target peak in dBFS (−1 dBFS is the loudest without clipping; −14 dBFS approximates the YouTube/Spotify target). Add an optional volume boost or cut.
- 3
Choose output format
Select MP3 for a smaller file or WAV for lossless 16-bit PCM output. Use WAV if you plan to edit or re-encode the result later.
- 4
Normalize and download
Click Normalize. The tool shows the original peak, output peak, and gain applied for each file. Click the download icon to save.
When do you need to normalize audio?
- A podcast recording is too quiet compared to other episodes in the feed
- A phone voice memo or interview recording is hard to hear without turning up the volume
- Multiple recordings at different volumes need to be consistent before editing
- A video's audio track is low after converting to MP3 from MP4
- Music downloaded at varying levels needs to match before creating a playlist
- A lecture or webinar recording has inconsistent speaker volumes
Target level quick guide
| Target | Use case | Notes |
|---|---|---|
| −1 dBFS | Podcasts, broadcast, general use | Maximum loudness without clipping — default choice |
| −3 dBFS | Music mastering with headroom | Leaves room for limiters and loudness meters in a DAW |
| −6 dBFS | Files for further editing | Safe headroom if the file will be mixed, EQ'd, or compressed |
| −14 dBFS | Streaming platform target (approx.) | YouTube, Spotify, Apple Music normalise to −14 LUFS integrated; peak and integrated loudness are not identical, but this is a reasonable proxy |
Peak normalization vs loudness normalization (LUFS)
This tool uses peak normalization: it finds the single loudest sample in the file and scales the entire file so that peak hits the target dBFS. It is simple, fast, and widely supported.
Loudness normalization (LUFS / EBU R128 / ReplayGain) measures perceptual loudness averaged over time and is used by streaming platforms to level tracks. A file with a −1 dBFS peak but mostly quiet content will still be turned down by Spotify to match its −14 LUFS target. For production work where you need precise LUFS control, use a DAW plugin (like FabFilter Pro-L or the free Youlean Loudness Meter). For everyday use — making a quiet recording audible, matching several recordings for playback — peak normalization here gets the job done in seconds without any software installation.
Frequently asked questions
What does normalizing audio do?
Normalization finds the loudest peak in your audio file and adjusts the volume so that peak hits a target level — typically −1 dBFS (just below the maximum digital volume). This makes quiet recordings as loud as possible without clipping, and brings inconsistently recorded files to a consistent volume.
What is dBFS and what target should I use?
0 dBFS is the loudest a digital signal can be without clipping. Everything below it is negative. −1 dBFS is the standard target for podcasts, broadcast, and general audio — it is as loud as possible without risk of distortion. −6 dBFS is safe for music that will be processed further. −14 dBFS approximates the integrated loudness target used by YouTube and Spotify (though their targets are in LUFS, not peak dBFS).
What is the difference between normalizing and boosting volume?
Normalization adjusts gain relative to the existing peak — so two recordings at different original volumes end up at the same peak level. Volume boosting applies a fixed gain to the entire file regardless of its current level. This tool lets you do both: normalize to a target peak, then apply an optional additional boost or cut.
Is there a risk of clipping when boosting volume?
Yes. If you normalize to −1 dBFS then add +3 dB boost, the output could reach +2 dBFS — which clips to 0 dBFS and causes digital distortion. The tool clamps all samples to [−1, 1] to prevent over-true-peak, but if the boost is large you will hear limiting at the loudest moments. Lower the target peak to leave headroom for the boost (e.g. −4 dBFS target + +3 dB boost = −1 dBFS output).
Is my audio uploaded to a server?
No. All processing uses the Web Audio API and runs entirely in your browser tab. Your audio file never leaves your device — there are no network requests during analysis or normalization. This is especially important for sensitive recordings like meetings, interviews, or personal voice memos.
What formats are supported?
MP3, WAV, M4A, AAC, OGG, FLAC, and OPUS — any format your browser can decode via the Web Audio API. Output is either 128 kbps MP3 (via lamejs) or 16-bit PCM WAV. Choose WAV if you plan to re-encode the file again later, as re-encoding MP3→MP3 adds a generation of quality loss.
Can I normalize multiple files at once?
Yes. Add as many files as you need and click Normalize All. They are processed one at a time so your browser stays responsive. All files in the batch use the same target peak, boost, and format settings.
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