What is True Peak

An audio file does not have to show any overs above 0 dB – and yet it can still distort after transcoding on a streaming service. True Peak reveals signal peaks that occur between samples and that a lossy codec can amplify even further. That is why the so-called Sample Peak is not enough.

What True Peak is and why Sample Peak is not enough

Digital audio is stored as a sequence of samples – discrete numerical values captured at regular time intervals. Sample Peak is the highest value reached by any of these samples. When you look at the Sample Peak, you only see what is written directly in the file.

But playback is not a discrete process. During digital-to-analogue (D/A) conversion, the signal is reconstructed into a continuous analogue form using an interpolation filter. And it is precisely between the samples – where no recorded value exists – that the reconstructed signal can reach a higher level than any individual sample shows. These peaks are called intersample peaks, and their maximum value is exactly the True Peak.

Digital samples (Sample Peak ≤ 0 dBFS) Reconstructed analogue signal Zone above 0 dBFS (clipping)

Hover over (or tap) the samples and the peaks of the curve to see the exact values. The values are exaggerated for clarity.

dBFS vs. dBTP – not the same thing

dBFS (decibels Full Scale) describes the level of the digital samples – what is written in the file. dBTP (decibels True Peak) describes the peak level of the reconstructed signal after D/A conversion.

A file with a Sample Peak of −0.1 dBFS can easily have a True Peak of +0.4 dBTP. A Sample Peak or dBFS measurement simply will not reveal this value – which is why True Peak is always measured for streaming.

Why True Peak only became a problem with streaming

Historical context: Older masters were made at a time when True Peak was not systematically measured – the tools were either not available or the metric was not taken into account. A large amount of archive material therefore contains intersample peaks exceeding 0 dBTP. This was not a major problem – until music started being encoded into lossy formats on a massive scale.

The spread of lossy compression – particularly the AAC, MP3 and Opus formats – as the standard distribution formats of streaming platforms changed the situation fundamentally. When encoding, these codecs work with frequency transforms and can cause the peaks at the decoder output to be higher than they were at the encoder input.

A recording with a carefully controlled Sample Peak below 0 dBFS can clip on the player side after passing through an AAC codec. That is why the Audio Engineering Society recommendation (document AESTD1008.1.21-9) sets a maximum True Peak of −1 dBTP at the input of a lossy codec for all content intended for streaming.

How True Peak is measured

Because True Peak represents peaks between samples, it cannot be read directly from the file – it has to be estimated. The algorithm according to the ITU-R BS.1770 standard (Annex 2) does this in three steps:

Resampling to a higher sample rate. The signal is upsampled to at least 192 kHz. The higher the sample rate, the more accurate the estimate – at 192 kHz the measurement error is usually below 0.6 dB, assuming a linear-phase reconstruction filter.

Finding the maximum value after resampling. After upsampling, the density of samples represents the continuous waveform of the signal faithfully enough. The highest sample in this upsampled signal is the estimate of the True Peak.

Expressing it in dBTP. The maximum value found is converted to a logarithmic scale. The result – a value in dBTP – is shown in the metering plugin or application. It can be positive, i.e. exceed 0 dBFS.

What happens if you exceed the True Peak limit

Exceeding the True Peak limit does not automatically lead to audible distortion – good-quality speaker systems or headphones with decent headroom will cope with it. The problem may only arise during playback or transcoding – on lower-quality devices or with lossy codecs. There are three typical scenarios:

Distortion during playback

The player's D/A converter cannot reconstruct a signal above 0 dBTP without clipping. The result depends on how the player is implemented – from slight, inaudible limiting to audible distortion.

Overs after transcoding

Lossy codecs (AAC, Opus, MP3) can amplify overs even further during encoding. A recording with a True Peak of −0.3 dBTP can have a True Peak of +0.5 dBTP or more at the decoder output after encoding.

Limiting by the platform

Some platforms actively deal with overs using their own limiter. This rescues playback but can change the sound of the recording – especially with material that has a lot of dynamics.

What True Peak to aim for on streaming

The major streaming platforms recommend the same maximum value:

−1 dBTP Recommended maximum True Peak for a master intended for streaming

Spotify Apple Music YouTube Tidal Amazon Music Deezer

Practical recommendation

The maximum target True Peak value for a master intended for digital distribution in general is −1 dBTP. When working with more dynamic material, or if you are not sure how your mastering limiter behaves, it is safer to stay at −1.5 to −2 dBTP – this gives you headroom for codec overs. In addition, Spotify explicitly recommends no more than −2 dBTP for masters louder than −14 LUFS.

True Peak vs. Sample Peak – the differences at a glance

Property	Sample Peak	True Peak
What it measures	The highest sample in the file.	The highest peak of the reconstructed signal.
Unit	dBFS	dBTP
Can it be positive?	No (max. 0 dBFS)	Yes (even above 0 dBTP)
Does it reveal intersample peaks?	No	Yes
Relevant for streaming	Partly	Yes – primarily
Recommended limit for distribution	no fixed standard (roughly below 0 dBFS)	−1 dBTP (AES standard / all platforms)

True Peak cannot be fixed after distribution

Once a recording is released on the platforms, the True Peak in the distributed file does not change. The audio file cannot be replaced after it has been sent to distribution – fixing it means removing the release from distribution, adjusting the master and releasing the recording again as a new release – with a delay and the risk of losing your statistics.

It pays to check the True Peak value before sending the release to distribution. The quickest way is the Master check tool directly in Artists Bez Labelu – it shows you the true peak after normalisation for each platform. Without logging in, you can use the online tool LUFS and True Peak check.