Bluetooth codecs explained: SBC, AAC, aptX and LDAC
The codec logo on the box matters much less than the marketing implies. Latency is the exception.
By the Let’s Compare Editorial Team · 2 min read · Updated September 24, 2026
Flip over any wireless headphone box and you'll find a row of codec logos: SBC, AAC, aptX, aptX HD, LDAC. They're presented as if picking the right one will transform what you hear. It won't. Of everything on that box, the codec is one of the least important specs.
Bluetooth codecs at a glance
| Codec | Max bitrate | Latency | Best for |
|---|---|---|---|
| SBC | up to ~345 kbps | High | Universal fallback |
| AAC | ~256 kbps | Moderate | Apple devices |
| aptX | 352 kbps | Moderate | Android |
| aptX HD | 576 kbps | Moderate | Hi-res on Android |
| aptX Low Latency | ~352 kbps | <40 ms | Video & gaming |
| LDAC | 330 / 660 / 990 kbps | High | Hi-res files, strong connection |
What a codec does
A Bluetooth audio codec compresses sound on your phone, sends it over a bandwidth-limited radio link, and decompresses it in the headphones. Codecs differ in how much data they push and how cleverly they compress it. SBC is the baseline every device supports. AAC is widely used, especially by Apple. The aptX family and Sony's LDAC are the "hi-res" options.
Start with the bitrate ceilings. Standard aptX tops out around 352 kbps and aptX HD around 576 kbps, while AAC is capped near 256 kbps. LDAC is adaptive: it steps between 330, 660 and 990 kbps depending on how stable the connection is, which gives it the highest ceiling of the mainstream codecs.
Why it rarely matters
Two things blunt the advantage of the high-bitrate codecs. Most people stream from services that are already lossy, so there's little extra detail for a fatter codec to carry. And driver tuning (plus, on earbuds, fit and seal) shapes what you hear far more than the last slice of bitrate. A well-tuned pair on AAC will beat a poorly tuned pair on LDAC every time.
LDAC's top 990 kbps mode isn't free, either. It needs a strong, close connection to hold and drops to a lower rate in a busy radio environment. Even in ideal conditions, with high-bitrate source files, the gap between a good AAC or aptX stream and LDAC is subtle.
Where codecs do count: latency
Lag is where the codec makes a difference you'll notice. Standard Bluetooth audio can drift far enough out of sync to bother you in video and games, and only the low-latency codecs fix that. aptX Low Latency, for instance, keeps delay under roughly 40 milliseconds, low enough for lips and audio to line up. If you regularly watch video or game on wireless headphones, low-latency support (or a dedicated low-latency mode) is worth more than any hi-res badge.
So buy headphones for their sound, comfort, noise cancelling and battery. Use the codec list as a tiebreaker. Check for a low-latency option if you need one, and otherwise don't let a logo make the decision.
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Sources & further reading
The facts and figures in this article come from the references below (some of them not in English), so you can check them yourself.
- Understanding Bluetooth codecs — SoundGuys
- Bluetooth Codecs: aptX, AAC, SBC und Co. erklärt — HIFI.DE (DE)