I am comparing not directly the sound but the compression used to deliver the music to you by looking at the best possible quality a service can deliver.

Comparison

This chart is largely based on data from 2022 and was only partially updated in 2025.

Service (Tier)	Lossless	Codec	Bitrate	Samplerate
YouTube	No	Opus	~100-140 kbit/s	48 kHz
YouTube Live	No	AAC	128 kbit/s	44.1 kHz
Spotify Lossless	Yes	FLAC	as much as codec requires	up to 24 bit / 44.1 kHz
Spotify App (Premium)	No	Vorbis	320 kbit/s	44.1 kHz
Spotify Web (Premium)	No	AAC	256 kbit/s	44.1 kHz
Spotify App (Free)	No	Vorbis	160 kbit/s	44.1 kHz
Spotify Web (Free)	No	AAC	128 kbit/s	44.1 kHz
Tidal High	Yes	FLAC	~1411 kbit/s (lossless)	44.1 kHz
Tidal Max	Yes	FLAC	as much as codec requires	up to 24 bit / 192 kHz
Apple Music	No	AAC	256 kbit/s	44.1 kHz
Apple Music Lossless	Yes	ALAC	as much as codec requires	up to 24 bit / 192 kHz
SoundCloud	No	MP3	128 kbit/s	44.1 kHz
SoundCloud (HQ)	No	AAC	256 kbit/s	44.1 kHz

Ranking the non-lossless offers based on my personal (a bit subjective but well-informed) knowledge:

1. Spotify App (Premium)
2. Apple Music, Spotify Web (Premium), SoundCloud (HQ)
3. YouTub, Spotify App (Free)
4. Spotify Web (Free), YouTube Live
5. SoundCloud

Please note that all lossless offers will deliver better quality than any lossy offer, meaning Tidal and Apple Music Lossless (which is included in the regular subscription) are better than e.g. Spotify or YouTube.

Which Service Should I use?

The one you like best: In reality Spotify, Apple Music (lossy), Tidal Premium and YouTube will sound good unless you reeeeaaaaaally care that much or have a very good system.

Even YouTube with it's low bitrate on all platforms sounds good enough because they use a very modern codec. Just make sure you actually listen to music and not the videos, as videos are likely uploaded with already compressed audio, especially community remixes or nightcore versions, thus lowering the audible quality significantly.

And also try to avoid SoundCloud's free offer for serious listening or louder than background music playback.

Do you need Hi-Res ?

Hi-Res means a bit depth above 16 bit and/or smaple rate above 44.1 kHz. And no, you do not need it, you shouldn't even be able to hear any difference if your playback system is working as it should.

Why? Because rates above 16 bit are only useful in a studio use-case. 16 bit has such a high dynamic range that you can't even hear the full range at the same time due to how your ear works. Technically, even 16 bit is overkill. And as for sample rates, higher rates allow capturing more frequiencies, but a human hear can't really hear more than 20 kHz and a sample rate of 44.1 kHz is already able to represent audio with 22 kHz. So no, Hi-Res is technically speaking snake oil and if you hear a difference, that likely has to do with the respective master used for the audio file or the architecture of your DAC being flawed. Keep in mind, this is only my opinion, but it should be pretty sound.

Annotations

Bitdepth is usually 16 bit if not stated otherwise.

YouTube (and YT Music) uses a presumably custom method to control the bitrate of their Opus encodes. It also uses AAC audio for older devices/browsers for which it uses a standard bitrate of ~128 kbit/s.

Tidal Max, while having trasitioned most of their Hi-Res library to FLAC, still serves some content through the propriotary Master Quality Authenticated format and needs special hardware to be decoded up to their original quality. If such hardware is not available, the file will not be decoded up to the same quality. MQA is also said to not be lossless, contrary to their marketing. Please research this topic yourself if you consider Tidal because of their Master releases.

Apple Music uses it's own implemntation of AAC (often referred to as qAAC), which is said to be a bit better than fdkaac or other encoders, but of course that opinion has been heavily discussed. I recommend looking up resources for this yourself.

Apple Music Lossless is not a different tier, it is available to every Apple Music subscriber as long as their device supports it.

All data gathered for the example comes either directly from the service's respective website (like Spotify, Apple Music, Tidal and SoundCloud HQ) or from personal tests using tools that download the offered audio stream and analyzing it (like with YouTube or SoundCloud free).

Which is the best codec?

This is partly very subjective and also dependent on the encoder for some codecs.

Genereally the codecs can be ranked in this order:
Opus > Vorbis > AAC > MP3

Ranking the encoding software:
opus > vorbis > qAAC/FDK-AAC > FFmpeg AAC > LAME (MP3)

FFmpeg (and Handbrake which is based on FFmpeg) use FFmpeg's AAC encoder, which is worse than FDK-AAC or qAAC but a bit better than LAME.

Generally most commerical services and software probably use FDK-AAC, with the exception of Apple.

Encoding at low bitrates (< 128 kbit/s) the ranking looks like this:
HE-AAC v2 > HE-AAC > Opus > Vorbis/AAC > MP3