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 and Tidal 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, Amazon Music and Tidal at −14 LUFS, Apple Music at −16 — plus a custom target from −30 to −6 LUFS.
- Two-pass normalization with a safe ceiling. Linear loudness normalization with a −1 dBTP true-peak ceiling, exported in the same format you uploaded.
FAQ
Is this LUFS normalizer free?
Yes. Anonymous users get 5 free processings per day across AudioKit's free tools — no account needed. 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 and no feature lock: the free result is the full result.
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). Normalization runs in two passes for precision, and a result banner reports the actual output loudness 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.