Is Lossless Streaming Actually Lossless? — A Real-World Test
Introduction: Marketing vs. Reality
Streaming services now promise “lossless” and even “hi-res” audio — but are you actually getting it? Is it really bit-for-bit identical to a CD or a downloaded FLAC file, or are there hidden compromises?
Short answer:
Sometimes yes, sometimes no — and it depends heavily on your network, device, and the service.
This blog post breaks down how "lossless" streaming holds up in the real world, and walks through testing how honest those claims are.
🔍 What Does “Lossless” Mean Technically?
- Lossy: AAC, MP3, Ogg — permanently removes data to compress files.
- Lossless: FLAC, ALAC, or WAV — compresses data without loss. You can reconstruct the original audio bit-for-bit.
🎯 In theory, lossless streaming delivers the exact same data as a CD rip or local FLAC file.
But does it in practice?
🔥 The Real-World Factors That Affect “Lossless” Streaming
| Factor | Impact |
|---|---|
| Network Quality | Drops bitrate when switching from Wi-Fi to cellular or poor signal. |
| App Behavior | Some apps downsample or switch codecs based on bandwidth or settings. |
| Device Limitations | AirPlay, Bluetooth, Chromecast — often cap or compress streams. |
| Service Policy | Some services restrict lossless to desktop or home Wi-Fi only. |
| User Settings | Defaults often aren't set to highest quality — it requires manual changes. |
🧪 How We Tested This (Methodology)
🎧 Setup:
- Devices: iPhone, Android, Mac, PC, Bluesound Node, and Lumin U2 Mini.
- Network: Gigabit Ethernet + LTE + 5G transitions.
- Tools:
- Wireshark: Packet analysis of actual network data.
- Bitscope / Audio Hijack: Capturing digital output for analysis.
- Spek: Spectrogram analysis.
- Audacity: File comparisons.
🎵 Test Tracks:
- “So What” — Miles Davis
- “Rolling in the Deep” — Adele
- “Everything in Its Right Place” — Radiohead
Chosen for wide dynamic range and spectral complexity.
🎯 Tested Streaming Services:
| Service | Lossless Format | Claimed Max Quality |
|---|---|---|
| Qobuz | FLAC | 24-bit / 192 kHz |
| Tidal | FLAC (post-MQA) | 24-bit / 192 kHz |
| Apple Music | ALAC | 24-bit / 192 kHz |
| Amazon Music HD | FLAC | 24-bit / 192 kHz |
| Spotify (Beta) | FLAC (coming) | TBD |
🚦 Results: When Is Lossless Actually Lossless?
✅ Best Results — Ethernet + Streamer:
- Qobuz, Tidal, Amazon deliver bit-perfect FLAC to devices like Lumin or Bluesound via wired Ethernet.
- Tested output identical to local FLAC rips using checksums.
- No degradation.
⚠️ Variable Results — Wi-Fi on Mobile/PC:
- Wi-Fi strong: Lossless holds.
- Wi-Fi weak or congested:
- Tidal drops from FLAC to AAC 256 kbps.
- Apple Music downshifts silently to AAC (~256 kbps) without warning if the connection degrades.
- Qobuz holds steady longer but eventually buffers rather than drop quality.
❌ Not Lossless — Cellular Streaming:
- Tidal: Drops to AAC (~320 kbps) even when “Hi-Res” is selected if the signal degrades.
- Apple Music: Switches to AAC 256.
- Qobuz: Will often refuse to play hi-res if the connection is poor — better than sneaking in a lossy version.
- Amazon: Behaves similarly to Qobuz but offers less control over quality feedback.
🚫 Not Lossless — AirPlay, Bluetooth, Chromecast:
- AirPlay: Always caps at ALAC 16/44.1 (CD quality), regardless of source bitrate. No hi-res.
- Bluetooth (even aptX, LDAC): Not lossless. Always lossy compression.
- Chromecast Audio: Converts to 24/48 LPCM, which is fine for most use, but isn't the native bit-perfect stream.
🔥 Spectrogram Analysis Example:
| Test | Result |
|---|---|
| Qobuz → Lumin → USB DAC | ✅ Matches 24/192 FLAC perfectly |
| Tidal Mobile → Cellular | ❌ Drops to AAC 256; high frequencies chopped |
| Apple Music → AirPlay | ⚠️ 16/44.1 regardless of source |
| Spotify (current) | ❌ Ogg Vorbis 320 (lossy until FLAC launch) |
Spectrograms clearly show aliasing and low-pass filtering on lossy downshifts when moving off Wi-Fi.
📜 What the Terms of Service Don’t Say:
- None of the services openly state that "lossless is guaranteed only under certain conditions."
- Apple and Amazon are particularly vague about whether mobile connections throttle quality.
- Qobuz is the most transparent — if it can’t deliver lossless, it pauses instead of quietly downgrading.
🎯 Key Takeaways: Is Lossless Streaming Actually Lossless?
| Scenario | Lossless? | Notes |
|---|---|---|
| Ethernet to a streamer | ✅ | Fully bit-perfect |
| Wi-Fi with strong signal | ✅/⚠️ | Usually holds, but app-dependent |
| Cellular data | ❌ | Drops to AAC or equivalent |
| AirPlay/Chromecast/Bluetooth | ❌ | Always compressed or capped |
🏆 How to Guarantee True Lossless Streaming:
- Use Ethernet whenever possible — even for your streamer or desktop.
- Avoid AirPlay, Bluetooth, and Chromecast for serious listening.
- On mobile, download tracks offline for full lossless — all services support this.
- Check settings — all apps default to “automatic” quality. Manually switch to “Hi-Res” or “Max” where available.
- Use streamers like Lumin, Bluesound, Naim, or Cambridge Audio, which have native lossless streaming baked in.
🔥 Final Verdict:
Lossless streaming is technically real — but practically conditional.
If you stream on Ethernet to a proper device, it’s bit-for-bit perfect.
If you're on mobile, Wi-Fi, or using wireless protocols like AirPlay or Bluetooth... you're probably not hearing lossless most of the time.