Audex Trace vs LosslessSwitcher: what's different.
LosslessSwitcher is a useful free tool for automatic sample-rate switching. Trace is for Apple Music listeners who also want to see what is playing, whether the output matches, and, in Trace Pro, what is coming up next in Playing Next.
If automatic switching is all you need, use LosslessSwitcher.
LosslessSwitcher is free and open source, and it does the one thing most people want: it switches your DAC's sample rate to match what Apple Music is playing. You do not need to pay for that.
LosslessSwitcher switches. Trace also shows what is playing.
LosslessSwitcher is built around automatic sample rate switching. Trace is built around showing the codec, sample rate, and bit depth of what is playing and whether your output matches it, and it switches sample rates too.
When the rate changes around a track change.
Music prepares the next track before the current one ends, and the prepared track writes its format to the log while the current one is still playing. It does this with Song Transitions, AutoMix, and Crossfade off too, so turning them off does not prevent an early switch. Two open LosslessSwitcher issues describe what happens when a switcher applies that line. In #159 (January 2025), the bit depth and sample rate follow the next song in the playlist instead of the one playing. In #231 (September 2026), the rate is right at the start of a track and then changes partway through to the next track's rate. Pull request #225, which would run detection only on a real track change, resume, or seek, was still open and unreleased on November 3, 2026.
Trace's readout and Auto Sample Rate Match stay on the track that is playing until the next one starts, so a prepared next track does not move them. This is best effort. Within a track the readout is live: if Music's stream drops to a lower quality partway through a song, or comes back up, the readout changes when that happens. The mid-track switch guide has more on the problem and how to check for it.
Song Transitions, AutoMix, and Crossfade cause a separate delay. With one of them on, Music plays two tracks at once around each change. Trace's readout still changes when the next track starts. Auto Sample Rate Match waits until Music has finished handing over from the previous track, because changing the rate mid-blend makes Music cut the blend off and start it again. So the switch can land a few seconds after the track change, up to about 20 seconds in the worst case, and macOS resamples the new track until then. The developer tested this with AutoMix on macOS 26; macOS 15 has not been checked with these features on.
What each tool is built to show.
| Feature | Audex Trace | LosslessSwitcher |
|---|---|---|
| Menu bar sample rate display | Yes | Yes |
| Full playback readout (codec / sample rate / bit depth) | Yes | Partial: sample rate and optional bit depth, no codec readout |
| Output device and sample rate match display | Yes | No |
| Playing Next (Trace Pro) | Yes. Upcoming queue, artwork, scrolling, queue editing, quality estimates, and skip warnings. | No |
| Skip-risk indication | Yes, in Playing Next (Trace Pro) | No |
| Automatic sample rate switching | Yes | Yes |
| When Music prepares the next track early | Waits until that track starts. With Song Transitions, AutoMix, or Crossfade on, the switch waits for the handover, up to about 20 seconds. | Open issues #159 and #231 report early switches to the next track's rate. |
| Price | $29.99 one-time | Free, open source |
Check your own Mac before paying.
Detection and readout accuracy vary across DACs, interfaces, and configurations.
Trace's free Playback Verification is there for that. Download it, play a few tracks, and compare what Trace reports with your DAC's own display. If the numbers match on your Mac and your hardware, buy Pro. If they do not, you do not need to pay.
Playback-format detection currently requires a macOS administrator account. Standard user accounts cannot access the local playback logs Trace needs, so Playback Verification and live playback-format detection do not work there.
What about SyncHz (formerly Choritsu)?
SyncHz is another free, open-source option: a menu-bar app for macOS 15 and later that works with Apple Music only. It handles automatic sample-rate switching by reading Music's own log, and its README describes it as the same core idea as LosslessSwitcher in a different build.
It also adds a driverless parametric headphone EQ with AutoEq and PEQdB presets, a now-playing panel, device and volume control, and 12 languages. Its README notes that playback is not bit-perfect while the EQ is on.
For detection, its README says it reads Music's log, locks a rate only after enough evidence, resets the lock on every track change, and is debounced so it does not flap mid-track. The README does not say how it handles a prepared next track or Song Transitions, AutoMix, and Crossfade. SyncHz is not notarized yet, so the README has you clear the quarantine flag in Terminal before the first launch; Trace is signed and notarized.
Its panel also shows source and output side by side with the codec, bit depth, and Apple's quality tier, so on the readout itself the two tools overlap. What SyncHz's README does not describe is Trace Pro's Playing Next: the upcoming queue, artwork, quality estimates, and skip warnings. Trace has no EQ, and Trace Pro is a $29.99 one-time purchase. If automatic switching plus a headphone EQ is what you want, SyncHz is a good free choice.
It depends on what you want to see.
| Use LosslessSwitcher if | Trace is for you if |
|---|---|
| Automatic sample rate switching is all you want. | You want to see the codec, sample rate, and bit depth of what is playing instead of taking the Lossless label on trust. |
| You prefer free, open-source tools. | You want confirmation that your output device matches the source. |
| You already trust your setup and do not need to see what is playing. | You want Trace Pro's Playing Next, including queue quality and skip-risk visibility, before a track plays. |
| Your music stays at one sample rate, so an early switch would not change anything. | Your playlists mix sample rates, or you keep Song Transitions, AutoMix, or Crossfade on. |
| You do not need a paid Apple Music companion app. | You are willing to pay $29.99 once, after verifying detection works on your own hardware. |
What the free download includes.
Now Playing with playback controls, track metadata and artwork, the player window, menu bar panel and notch, keyboard shortcuts, and Playback Verification. Playing Next is part of Trace Pro. Audex Trace does not modify, enhance, record, or upload audio.