Free tool
Quality profile advisor
Choosing a lossless cutoff feels free until several Flows start fetching. Work out what a tier costs in disk and bandwidth, and whether it suits what you listen on.
Retained library size
234 GB
Size per album
0.23 GB
Approx. upgrade traffic
0 GB
All tiers side by side
| Tier | Per album | 10,000 tracks | Character |
|---|---|---|---|
| MP3 128 | 0.04 GB | 38 GB | Roughly transparent on portable speakers |
| MP3 192 | 0.06 GB | 56 GB | Often called the practical compromise |
| MP3 256 | 0.07 GB | 75 GB | Hard to distinguish from lossless on most systems |
| MP3 320 | 0.09 GB | 94 GB | The practical ceiling for lossy |
| FLAC standardcutoff | 0.23 GB | 234 GB | 16/44.1 or lower. Transparent for almost all listening |
| FLAC 24/48 | 0.47 GB | 469 GB | Genuinely higher rates. Audible on good hardware |
| FLAC 24/96 | 0.70 GB | 703 GB | Rarely worth the storage for most listeners |
| FLAC 24/192 | 1.41 GB | 1406 GB | Archive territory. Needs a very good chain to hear |
Assumes a four-minute average track and a ten-track album. Actual sizes vary with duration, and upgrade traffic estimates assume roughly a fifth of your library sits below the cutoff.
How the cutoff actually behaves
One profile applies to every download. Each quality tier is either enabled or not, and one enabled tier is marked as the cutoff. From those two facts: an enabled tier at or above the cutoff is Preferred, an enabled tier below it is an Upgrade candidate, and a disabled tier is Below floor.
So setting FLAC standard as the cutoff with MP3 still enabled is a coherent configuration. You accept lossless normally, and Aurral tries to improve the lossy files you already have without treating them as errors.
Why the file is verified rather than trusted
Search results lie about format and bitrate. Aurral uses names and bitrates to rank candidates but never accepts a file on that basis. After the download it reads the real file and rejects it if the format, bitrate, sample rate or bit depth does not match an enabled tier. A file of unknown quality is rejected outright.
This is the reason the tier you pick actually means something. A 320 kbps MP3 labelled as FLAC does not pass a FLAC tier.
Upgrades queue behind missing tracks
If both are pending, a track you do not have at all is downloaded first. Aurral searches slskd, then Usenet, then deemix, stopping at the first source giving a valid, better file. yt-dlp is deliberately excluded because it cannot guarantee a better version of a specific recording.
The interval between checks defaults to two days and ranges from one to 365. It applies per track, so a large library spreads its upgrade cost over time rather than all at once.
What this tool cannot tell you
It estimates from bitrate and an assumed four-minute track length. Actual file sizes vary, and your storage needs also depend on how many Flows are running and how often you keep tracks rather than letting them rotate out. Treat the numbers as a comparison between tiers rather than a precise figure.
Frequently asked questions
Should I use FLAC or MP3 320?
FLAC standard if your playback chain resolves above 48 kHz, which covers most headphones and desktop setups. MP3 320 if it does not, or if storage and bandwidth are the binding constraint.
Is FLAC standard really transparent?
At 16/44.1 and below, yes for almost all listening. Differences are measurable in lab tests but hard to hear outside a controlled comparison on good hardware.
What if I do not know what my playback chain resolves?
Headphones and desktop DACs usually handle 24/48 without trouble. Bluetooth does not, so with Bluetooth the answer is MP3 256 or better.
What does automatic upgrades cost?
Upgrade downloads queue behind missing-track downloads and only run at your configured interval, typically every two days. They also temporarily hold two copies of a track while the replacement is verified.
Set it and let it improve over time
Start at FLAC standard with upgrades on. Aurral improves what you already have gradually rather than demanding everything be replaced.