LUFS Meter (Loudness Meter)
This LUFS meter applies K-weighting to your microphone and shows momentary (400 ms), short-term (3 s) and integrated loudness in LUFS-style units.
ℹ Approximate and relative — not a certified loudness measurement. A browser mic is uncalibrated and the OS may apply automatic gain, this meter is mono / single-channel, and the gating is simplified. Use it to watch loudness change and compare momentary vs short-term — not to certify a file to a spec. For compliant LUFS (ITU-R BS.1770 / EBU R128), measure the file in a proper meter. Nothing is recorded or uploaded.
Microphone
Loudness
What LUFS Means
LUFS (Loudness Units relative to Full Scale) — also written LKFS in broadcast contexts — estimates how loud audio sounds to people, not just its raw level. It applies K-weighting — a high-pass that removes low-frequency rumble plus a high-frequency shelf that boosts treble slightly, approximating the ear’s sensitivity — then measures the mean square energy over a time window. Momentary uses a 400 ms window, short-term a 3 s window, and integrated averages the whole program with absolute gating (blocks below −70 LUFS) to ignore silence. The standard is defined in ITU-R BS.1770 and operationalized by EBU R128 for European broadcast.
This meter implements that idea with real K-weighting filters, but it reads your microphone, which is uncalibrated, mono, and subject to the system’s automatic gain control (AGC). So the numbers are a useful relative guide — great for watching loudness rise and fall, comparing a voice at different distances, or getting a feel for the difference between momentary peaks and short-term average level — but they are not a certified loudness measurement. If you need a reference tone to calibrate against, you can generate a 1 kHz reference tone and note how the meter responds at a known level.
Why it’s not a substitute for a file meter
Compliant loudness measurement for streaming or broadcast is always performed on the actual audio file with calibrated, multi-channel, fully-gated metering — not from a live microphone feed. A live mic introduces room acoustics, microphone frequency response, distance variation, and OS-level automatic gain — none of which belong in a loudness specification. Common delivery targets include −14 LUFS integrated for music streaming platforms (Spotify, Apple Music, YouTube Music) and −23 LUFS for EBU R128 broadcast. Podcast dialogue often targets −16 LUFS integrated. Treat this meter as a learning and live-monitoring tool; if you need a simple A-weighted SPL or RMS level instead, the live decibel meter is a faster option. Use the loudness normalization calculator to compute the exact gain offset once you have a reference number from a file meter.
LUFS vs dBFS vs True-Peak: what each number actually measures
dBFS (decibels relative to Full Scale) measures the sample peak level — the highest digital sample value in the waveform, expressed as a ratio to the maximum the format can hold. It says nothing about how loud the audio sounds, only how close the largest sample is to clipping. LUFS, by contrast, is a time-averaged, K-weighted measure of perceived loudness: two tracks at the same dBFS peak can sound dramatically different in loudness, which is exactly the problem LUFS was designed to solve.
True-peak (dBTP) goes one step further: it uses oversampling to detect inter-sample peaks — points between digital samples where the reconstructed analogue waveform can momentarily exceed 0 dBFS even when every individual sample is below it. Lossy codecs (MP3, AAC) can amplify these overshoots during encode, causing audible distortion. The widely accepted safety ceiling is −1 dBTP, which leaves headroom for codec processing. Practical streaming targets are approximately −14 LUFS integrated (Spotify, YouTube, Tidal) and −16 LUFS (Apple Podcasts), each paired with a −1 dBTP ceiling. Use the peak / level analyzer to check peak and RMS together, and the loudness normalization calculator to find the gain adjustment needed to hit a target.