A free LUFS meter for finished audio files
This LUFS meter tells you how loud a song, podcast episode, voice-over or video soundtrack really is, the way streaming services and broadcasters measure it. Drop in one file or a batch and you get the integrated loudness in LUFS, the loudest 3-second and 400-millisecond moments, the loudness range (LRA) and the true peak — plus a graph of loudness over time and a table comparing your file with Spotify, Apple Music, YouTube, podcast, EBU R 128 and ATSC A/85 targets.
It only measures; nothing about your file changes. Everything runs in your browser, so unreleased masters and private recordings never leave your device. When a target needs a different level, the Audio Normalizer uses the same BS.1770 meter to apply it.
How to use the LUFS Loudness Meter
- Drop one or more audio or video files on the box — MP3, WAV, FLAC, M4A, OGG, Opus, WebM or MP4 — or press Measure a generated test signal.
- Read the big number: the integrated loudness of the whole file. Below it are max short-term, max momentary, loudness range, true peak, sample peak and peak-to-loudness ratio.
- Look at the graph to see where the loud and quiet passages are; pick a target under Show on the graph to draw it as a dashed line, or enter a custom one.
- Check the Your file column: how much each platform would turn the file down, or how much gain a specification needs, and whether the true peak would then pass.
- Click another file in the list to compare, and use Copy report or Download CSV to keep the numbers.
LUFS Loudness Meter features
ITU-R BS.1770-4 integrated loudness
K-weighting, 400 ms blocks every 100 ms, the −70 LUFS absolute gate and the −10 LU relative gate. The selftest checks EBU Tech 3341 signals to ±0.1 LU.
Short-term, momentary and LRA
Short-term (3 s) and momentary (400 ms) loudness every 100 ms, and loudness range per EBU Tech 3342 (10th to 95th percentile of gated short-term values).
True peak
Four-times oversampling below 96 kHz catches inter-sample peaks that a sample-peak meter misses — the ones that clip after MP3 or AAC encoding.
Platform targets with sources
Each target links to the platform’s own page or the standard, with the date it was checked; targets a platform does not publish are marked as such.
Loudness graph and CSV
See the whole file at a glance and export the 100 ms readings for a spreadsheet.
What the numbers mean
- Integrated loudness (LUFS) — the gated average of the whole file. This is the number platforms normalise to. LUFS and LKFS are the same unit; 1 LU equals 1 dB.
- Short-term — loudness over the last 3 seconds. Its maximum shows the loudest passage, such as a chorus.
- Momentary — loudness over the last 400 ms, which follows single words and drum hits.
- Loudness range (LRA) — how much the loudness varies, in LU. Pop masters often sit around 4–8 LU, film and classical music far higher; spoken word is usually lower. It is not recommended for files under a minute.
- True peak (dBTP) — the highest level of the reconstructed waveform, between samples. Keep it at −1 dBTP or lower for streaming.
- PLR — true peak minus integrated loudness: a rough guide to how much dynamic punch is left.
Loudness targets at a glance (checked 25 October 2026)
Streaming services mostly turn loud tracks down and leave quiet ones alone, so mastering much louder than their target gains nothing but lost dynamics. Broadcast standards are delivery specifications: a programme should arrive at the target.
| Platform or standard | Target | Peak limit | Status |
|---|---|---|---|
| Spotify (music) | −14 LUFS (Loud −11, Quiet −19) | −1 dBTP; −2 dBTP above −14 LUFS | Published by Spotify |
| Apple Music Sound Check | About −16 LUFS (reported) | At least 1 dB headroom | No number published by Apple |
| YouTube | About −14 LUFS (measured) | — | No number published by YouTube |
| Apple Podcasts | −16 LKFS ±1 dB | −1 dBFS | Published by Apple |
| EBU R 128 (v5, 2023) | −23.0 LUFS | −1 dBTP | Standard |
| ATSC A/85:2026-07 | −24 LKFS (≈ ±2 dB) | −2 dBTP | Standard |
Accuracy and limits
- Mono files are measured as one channel, as BS.1770 specifies, so they read about 3 LU lower than the same sound on two stereo channels. Some podcast tools add 3 LU for mono; this meter does not.
- Surround files are folded to stereo before measuring, so their reading can differ from a 5.1 meter that weights the surround channels.
- Lossy files are measured as decoded. MP3 and AAC encoding can raise the true peak by a fraction of a dB, so measure the file you will actually deliver.
- The meter reads a whole file; it doesn’t listen to a microphone live. For room levels in dB SPL see the Decibel Calculator.
LUFS Loudness Meter FAQ
How do I check the LUFS of a song?
Drop the song on this LUFS meter. The big number is its integrated loudness; the table shows how it compares with Spotify, Apple Music, YouTube, podcast and broadcast targets.
What LUFS should I master to for Spotify?
Spotify normalises to −14 LUFS on its default setting and recommends a true peak of −1 dBTP, or −2 dBTP for masters louder than −14 LUFS. Louder masters are simply turned down.
What is a good LUFS for a podcast?
Apple Podcasts asks for around −16 LKFS with ±1 dB tolerance and true peaks no higher than −1 dBFS; −16 LUFS is a common choice everywhere.
Is this loudness meter free and accurate?
Yes. It is free with no sign-up, and it follows ITU-R BS.1770-4 with EBU Tech 3341 and 3342; the built-in test checks reference signals to within 0.1 LU.
What is the difference between LUFS and dB?
dBFS measures signal level; LUFS measures perceived loudness with a frequency weighting and gating. A change of 1 LU is the same as 1 dB of gain.
Why is my true peak higher than my sample peak?
The real analogue waveform can rise between two digital samples. The true-peak reading estimates that by oversampling; it is the value that matters for clipping after encoding.
Does it change my file?
No. It only measures. To reach a target, use the Audio Normalizer.