Lossy Vs Lossless – What’s the Difference

I recently talked about the difference between FLAC and WAV files. In that comparison, I explained that they’re both lossless as compared to say an MP3 which is lossy. Let’s talk lossy vs lossless and what the key difference is between them.

Lossy vs Lossless

So, lossy vs lossless – what’s the difference?

Generally we’re talking about lossy vs lossless it’s in terms of compression.

A lossless file is compressed but has no loss in quality. Conversely, a lossy file is compressed but results in a loss in quality.

A FLAC file is an example of a compressed format which is appreciably smaller than a WAV file (uncompressed, lossless), at least 50% on average smaller, but there’s zero difference in the audio itself.

If anyone tells you they can tell the difference between FLAC and WAV files, just smile and try to keep it to yourself that you know better because they’re literally the same thing sonically.

An MP3, on the other hand, is an example of a compressed format which is even smaller than a FLAC file (90% smaller on average) but DOES result in a loss in quality.

The standard bit rate for a WAV file is 1411. When you consider that the HIGHEST quality MP3s have a bit rate of 320Kbps, it’s understandable that there’s some tradeoff in quality to achieve that file size.

Still, the process of altering the audio signal during the compression process, known as perceptual coding, is good enough to where an MP3, particularly at its highest bit rate, results in an imperceptible difference in audio quality for most people even with the sound lost.

This is why a lot of audio, particularly podcasts, are still offered in MP3 format; the difference to most anyone is negligible, and when it’s more about talking rather than music it’s especially so.

Even the biggest music streaming platform, Spotify, plays music in either OGG or AAC formats.

Comparable to MP3s in file size but higher in quality, Spotify allows premium members to playback music in these lossy formats up to 320Kbps where there’s roughly zero difference in perceived quality, particularly AAC.

This makes sense considering the huge library Spotify has, not to mention data usage concerns for its mobile users. Smaller file sizes mean less data is consumed to play the media, so it’s a necessity on both ends.

Speaking of types of audio formats, here is a graphic to compare all of the most popular audio format types, whether they’re lossy vs lossless, and more information on each:

But there you go: lossless refers to no drop in audio quality whereas lossy has some form of drop in audio quality for the sake of (substantially) smaller file sizes.

Whether or not the drop in quality is palpable is in the ear of the listener!