aptX is a Bluetooth audio codec, a method for compressing and sending sound wirelessly to headphones or speakers. It aims for better sound quality and lower delay than the basic Bluetooth codec. To use it, both your phone or computer and your headphones must support aptX. It was developed by Qualcomm and is common on many Android phones and wireless headphones.
Why this happens
Bluetooth has limited bandwidth, so audio must be compressed before it is sent. The codec is the set of rules that does this. The standard codec, called SBC, works everywhere but is fairly basic.
aptX is an alternative codec designed to sound better and feel more responsive. There are several versions. Standard aptX targets good quality, aptX HD aims for higher resolution audio, aptX Low Latency reduces the delay for video and games, and aptX Adaptive adjusts quality and latency on the fly.
Both ends of the connection must support the same codec. If they do not share aptX, they fall back to a codec they both have, usually SBC.
Is this normal?
Yes. Using a codec like aptX, SBC or AAC is a normal part of every Bluetooth audio connection. Your devices pick the best one they both support automatically.
Does it cause any problems?
Not usually. The main limit is compatibility. Apple devices do not support aptX and use AAC instead, so aptX headphones paired to an iPhone will use AAC. aptX also cannot make a low quality audio source sound better than the original.
How to fix or check it
- Check that both your phone or computer and your headphones list aptX in their specifications, since both must support it.
- On Android, pair the headphones, then open the Bluetooth device settings to see or choose the codec, if your phone allows it.
- For advanced users on Android, Developer options include a Bluetooth audio codec selector.
- On Windows, aptX works if the Bluetooth hardware and driver support it. Update your Bluetooth driver if it is missing.
- On an iPhone or Mac, expect AAC rather than aptX, as Apple does not include aptX.
- If sound cuts out, move closer to the source and reduce interference, or switch to a more stable codec.
Frequently asked questions
Is aptX better than SBC?
aptX generally sounds a little better and can have lower delay than the basic SBC codec, especially at its HD and Adaptive levels. The difference is subtle for casual listening.
Does the iPhone support aptX?
No. Apple devices use the AAC codec instead of aptX. aptX headphones still work with an iPhone, they just connect using AAC or SBC.
Do I need aptX for good Bluetooth sound?
No. AAC and even SBC can sound fine. aptX is a nice extra if both devices support it, but it is not essential for enjoyable wireless audio.