How it works
- Drop your audio file. MP3, WAV, FLAC, AIFF, OGG or M4A up to 500 MB — it's decoded locally, nothing is uploaded, and the loudness measurement is free.
- Read the measurement. Integrated loudness (LUFS), true peak (dBTP) and loudness range (LRA), compared against the Spotify, YouTube, Apple Music, Amazon Music, Tidal and Deezer targets.
- Pick a target and normalize. Choose Spotify −14, YouTube −14, Apple Music −16 or a custom value, then download the normalized file in your original format.
Features
- 100% in your browser. Measurement and normalization run locally with FFmpeg WebAssembly — your master never leaves your computer.
- Full BS.1770 loudness readout. A LUFS meter for the whole file: gated integrated loudness, true peak in dBTP and loudness range (LRA).
- Real streaming targets. Spotify, YouTube and Tidal at −14 LUFS, Deezer at −15, Apple Music at −16 (estimates from named, dated sources); for Amazon Music the target varies by source — plus a custom target from −30 to −6 LUFS.
- Album mode (Premium). Drop several tracks: one common gain is computed on the loudness of the whole album, so the level differences between your tracks are kept; each track's true peak stays at or below −1 dBTP. All tracks are downloaded in a single ZIP.
- Verified normalization with a safe ceiling. A simple gain when your peaks allow it, otherwise a 4× oversampled true-peak limiter or gain only — your choice, announced before export. The exported file is re-measured (true peak at or below −1 dBTP), in the same format you uploaded.
FAQ
Is this LUFS normalizer free?
Yes. Without an account you get 2 free processings per day across AudioKit's free tools; with a free account, 5 per day. Measuring your file's loudness is not billed at all: only the normalized export counts toward the quota. If you need more, AudioKit Premium removes the daily limit. There's no watermark: the free single-track result is the full result. Only album mode (several tracks normalized together, ZIP download) is reserved for Premium.
Is my audio file uploaded to a server?
No. Both the measurement and the normalization run entirely in your browser, using FFmpeg compiled to WebAssembly: your file is processed on your own machine and never leaves it. The only network call is a tiny anonymous counter that tracks your daily free quota.
Which audio formats are supported?
MP3, WAV, FLAC, AIFF, OGG and M4A files up to 500 MB. The normalized file is delivered in the same format you uploaded — a WAV master stays a WAV, an MP3 stays an MP3. If your file is in another format, run it through our free audio converter first.
How accurate is the LUFS measurement?
The meter uses FFmpeg's ebur128 filter, which implements the ITU-R BS.1770 / EBU R128 standard — the same measurement streaming platforms and DAW loudness meters rely on. You get gated integrated loudness, true peak in dBTP and loudness range (LRA). The exported file is measured again after encoding, and a result banner reports its actual loudness, true peak and range so you can verify the target was hit.
What LUFS target should I use for Spotify?
Aim for −14 LUFS integrated with a true peak at or below −1 dBTP — exactly what this tool's Spotify preset applies. Keep in mind Spotify normalizes playback anyway: mastering much louder than −14 LUFS just gets turned down, and the extra limiting costs you dynamics for nothing. Master for the sound you want, check the integrated value, and leave −1 dBTP of true-peak headroom for lossy encoding.