01
Drop the file
WAV, MP3, AAC, FLAC or OGG, up to 1 GB. Several at once if you want to compare a master with its MP3.
Free · A Squaresmile app
Is it too loud? Drop the file and know.
LoudSense shows what Spotify, Apple Podcasts or the broadcaster will see: peak, true peak, clips, LUFS and loudness range on a waveform — and a verdict per platform with the fix in dB. The file never leaves your device.
Free — 30-second signup, no card
Nothing uploaded, nothing stored
BS.1770-4 / EBU R128, true peak, LRA
How it works
Ten seconds from file to verdict.
02
It streams through
The browser decodes the file in chunks and measures as it goes. A two-hour recording costs the same memory as a jingle. Nothing is sent anywhere.
03
Read the panel
The waveform with red clip marks, cyan peak marks and the orange loudness curve; peak, true peak, clips, LUFS-M, LUFS-S, LUFS-I and LRA underneath. Play it back with a playhead.
04
Get the fix
Pick Podcast, Music, Broadcast or Live. Every platform row says OK, too loud, too quiet or peaks too hot — and by how many dB. Copy the report.
Features
Everything the platform will measure, before you upload.
True peak, not just peak
Sample peak says −0.2. True peak at 4× oversampling says +0.4. The second one is what the encoder and the platform see. LoudSense shows both.
Every clip, marked
Runs of full-scale samples are counted and drawn on the waveform, so you see where the mix hits the ceiling — and whether it was the master or the MP3 encoder.
Verdict per platform
Spotify, Apple Music, YouTube, Amazon, Tidal, Apple Podcasts, EBU R128, club and festival PA. Each with the consequence ("turned down by 2.3 dB") and the fix.
Loudness over time
The momentary-loudness curve over the waveform shows where an episode drifts and where a song's chorus lands, not just one number for the whole file.
Fix it, and preview the encoder
One click writes a WAV at the target with a true-peak limiter, original untouched. Encode preview runs your file through an MP3 encoder in the browser and shows what it does to the peaks — before you upload.
Private by design
No upload, no server, no storage. Your unreleased single or client episode stays on your machine — there is nothing to delete because nothing left.
Beyond the numbers
Built for the weekly episode and the album master.
Speech or music?
A strip under the waveform marks where the file is voice and where it is music, with a loudness for each — so you know whether the intro bed sits 4 dB over the host before the listener does.
Episode history
Every file you check is remembered in your browser, numbers only. The next episode of the same series shows a trend line and warns when episodes drift more than 2 LU apart.
Level-matched A/B
Play two files in sync and flip between them with the louder one turned down to match — compare the sound, not the volume. Or hear one file exactly as Spotify or Apple would play it.
Whole folders
Drop an album, a playlist or a season: up to 100 files analyse in name order, land in one compare table and give you the album loudness the services normalise by.
Your own targets
A station spec, a client's house rule, a festival's playback level: add it once with tolerance and ceiling, get a verdict row like any platform, and it follows you to the next device with your account.
Charts, CSV and the share sheet
A loudness histogram and the short-term curve with the LRA band, the curve as CSV for a spreadsheet, the panel as PNG — and on a phone with the app installed, LoudSense appears in the share sheet.
In the tool
Waveform, numbers, verdict.
FAQ
Quick answers.
Is my file uploaded?
No. LoudSense decodes and measures the file in your browser. Nothing is sent to a server, nothing is stored, and there is nothing to delete afterwards.
Why does my MP3 clip when the WAV master did not?
Lossy encoding changes the waveform slightly and can push peaks above full scale by up to a decibel. A master at −0.2 dBFS can come out of the encoder at +0.1. Leave about 1 dB of true-peak headroom before encoding, and check the encoded file.
How long a file can it handle?
Up to 1 GB. WAV and MP3 stream, so memory stays flat in Chrome, Edge and Safari 17+. Other formats and older browsers decode the whole file at once — 250 MB on a laptop, 60 MB on a phone.
Does it fix the file?
For loudness, yes: Fix it applies the gain and a true-peak limiter at the target's ceiling and downloads a WAV, original untouched. Encode preview shows what the MP3 encoder will do to your peaks before you upload. Noise, phase and DC still need the DAW.
Ready when you are
Check it before the platform does.
Create a free Squaresmile account and you're in — one login unlocks LoudSense and every other Squaresmile app.
