US television commercials
CALM Act, ATSC A/85 · −24 LKFS ±2 dB · peak −2 dBTP
Waiting for a file. Meets it Misses it Can’t tell No published figure: ask the station for its spec.
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Loudness checker
Drop in a spot, a promo or a read and see its integrated loudness in LUFS, its true peak in dBTP and its loudness range, checked against the broadcast and streaming specs voiceover work is held to.
Your file stays on your computer. It is read and measured by your own browser, and never uploaded or sent anywhere: not to us, not to anyone.
Drop an audio file here
WAV, AIFF, FLAC, MP3, M4A, Ogg or WebM · up to 200 MB and 20 minutes
Measuring
Results
No file yet. Choose or drop one above and its figures appear here, with how it sits against each spec below.
Couldn’t measure
· ·
- Integrated loudness
- — LUFS
- True peak
- — dBTP
- Loudness range
- — LU
- Max momentary
- — LUFS
- Max short-term
- — LUFS
- Sample peak
- — dBFS
- Average (RMS)
- — dBFS
- Length
- —
·
Against the specs for a finished spot
European television
EBU R 128 · −23 LUFS ±0.5 LU · peak −1 dBTP
Waiting for a file. Meets it Misses it Can’t tell No published figure: ask the station for its spec.
Spotify audio ads
Spotify Advertising · −16 LUFS ±1.5 · peak −2 dBTP
Waiting for a file. Meets it Misses it Can’t tell No published figure: ask the station for its spec.
Podcasts
Apple Podcasts recommendation · −16 LKFS ±1 dB · peak −1 dBFS
Waiting for a file. Meets it Misses it Can’t tell No published figure: ask the station for its spec.
US radio
No loudness law · The station’s spec
No published figure: ask the station for its spec. Meets it Misses it Can’t tell No published figure: ask the station for its spec.
Checking a dry read?
A dry read isn’t meant to hit the targets above: the mix does that. What a producer wants is room above your loudest word and an even level: a peak no higher than −3.0 dBFS and an average between −24.0 and −14.0 dBFS, the limits the SendScripts.to recorder checks every take against.
How it measures
- Integrated loudness
- ITU-R BS.1770: each channel K-weighted, left, right and centre counted once and the surrounds at 1.41, 400 ms blocks every 100 ms, gated at −70 LUFS and again 10 LU below the rest. A mono file counts once.
- True peak
- BS.1770’s own 48-tap filter, four times oversampled (twice at 96 kHz and up), across every channel. It can read a little above the highest sample.
- Loudness range
- EBU Tech 3342: 3-second readings every 100 ms, gated at −70 LUFS and 20 LU below their average, then the spread from the 10th to the 95th percentile.
- Momentary and short-term
- The loudest 400 ms and the loudest 3 seconds, read every 10 ms, as an EBU Mode meter shows them.
WAV and AIFF are read at their own sample rate, a piece at a time. FLAC, MP3, M4A, Ogg and WebM are decoded by your browser first, so what you measure is what it plays. Nothing is stored: close the tab and it is gone.