FAQ

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. The network tab shows only the page's own scripts.

How big a file can it handle?

Up to 1 GB. WAV and MP3 are streamed, so memory stays flat even for a three-hour recording in Chrome, Edge or Safari 17 and newer. Other formats, and MP3 in older browsers, are decoded whole, with a guard of 250 MB on a laptop and 60 MB on a phone.

Which formats work?

WAV (8 to 32-bit PCM and float), MP3, and whatever else your browser can decode — usually AAC/M4A, FLAC, OGG and AIFF. Video files are not supported.

Are the numbers the same as my DAW's?

Within a tenth of an LU for LUFS and LRA, and within a few tenths of a dB for true peak, which depends on the oversampling filter each tool uses. LoudSense is checked against the EBU reference signals in its own test suite. If your DAW reports sample peak only, LoudSense's true peak will read higher — that is the point of it.

Why does the MP3 clip when the WAV master did not?

Lossy encoding overshoots peaks by up to about a decibel. Leave 1 dB of true-peak headroom before encoding and check the encoded file. See Reading the numbers.

Does it fix the file?

For loudness, yes: Fix it applies the gain the verdict asked for and a true-peak limiter at the target's ceiling, then downloads a WAV and analyses it next to the original. It is a normaliser, not a mastering chain — no EQ, no compression. Noise floor, phase and DC problems still need the DAW.

Can I see what the MP3 encoder will do before I upload?

Yes. Encode preview encodes the file to MP3 in your browser at 128 to 320 kbps and measures the result. The preview row shows the true peak and clips the encoder added.

Does it cover audiobooks?

Yes. The Audiobook group checks Audible's ACX spec: RMS window, −3 dBFS peak ceiling and the −60 dB noise floor, which LoudSense estimates from the quietest passages.

Does it work on a phone?

Yes, for WAV and MP3 of any length in Chrome and recent Safari, and for other formats up to 60 MB. The panel is easier to read on a laptop.

Can I check several files at once?

Up to a hundred per drop — or choose a folder. A Compare table lists them side by side, the album loudness sits under it. The typical pair is the WAV master and its MP3.

Does it remember my episodes?

The numbers, yes — in this browser only, never the audio and never on the server. Files from the same series get a history block with a trend line so you can see if this week's episode matches the last ones. Clear it with one click.

Can I hear what normalisation will do?

Yes. In the A/B tab, pick a platform under "Hear A as" and press play: the file plays at the level the listener gets after that platform's turn-down. With two files loaded, A/B plays them level-matched so you compare the sound, not the volume.

Can I add my own target?

Yes — "My targets" under the verdict rows. Name, LUFS, tolerance, ceiling. Signed in, custom targets sync to your account.

Why do mono and stereo files with the same tone read differently?

Loudness sums both channels. The same tone on two channels carries twice the energy and reads 3 LU louder than on one. That is the standard, not a quirk.

Is LoudSense free?

Yes. It is free with a free Squaresmile account, which also unlocks every other Squaresmile browser tool.