# Check your master's loudness
Source: https://docs.aden.space/docs/help/free-tools/loudness-check

See your master's LUFS and true peak, and how much each streaming service turns it down, before you release.
The [Loudness check](https://tools.aden.space/loudness) shows how loud your master will play on streaming services. Free, no account needed, and the file never leaves your browser.

## Measure a master [#measure-a-master]

1. Open the [Loudness check](https://tools.aden.space/loudness).
2. Drop your master on the page, or press **Upload a master**. WAV, MP3, FLAC, AIFF and M4A work.
3. Read the results:
   * **LUFS**: the overall loudness. Streaming services adjust your track by this number.
   * **True peak**: the highest peak. Above -1 dBTP it turns amber, because peaks that high can clip once a service encodes the file.
   * **Range**: how much the loudness moves through the track.
4. Under **On streaming services**, see how much Spotify, Apple Music, YouTube, Amazon Music, Tidal and Deezer turn your master down, or up if it's quiet. Point at a value to read that service's rule.

Press **Check another** to measure the next file.

## Save it to Aden [#save-it-to-aden]

Press **Save as track**. Aden opens on a new track with the file, its BPM and its key. Without an account, you sign up first in that tab.

<Callout>
  A master that gets turned down a lot gains nothing from being louder. It just loses dynamics.
</Callout>

## Related [#related]

* [Compare your mix to a reference](/docs/help/free-tools/mix-reference-tool)