Bluetooth Codecs: AAC, aptX, LDAC, and What to Check

What a Bluetooth codec is

Bluetooth is the standard wireless connection for most headphones and earbuds. The Bluetooth Special Interest Group describes Bluetooth Classic as the radio used for audio streaming. To send sound over that radio, the audio is compressed with a codec, a short name for encoder-decoder. The codec defines how the audio data is packaged and transmitted.

A codec is not something you see on the outside. A listing may name one, but even if it doesn't, every Bluetooth headphone uses a codec by default. The standard baseline is often called SBC, which is supported by most Bluetooth audio devices. If you want to know which codec a pair uses, check the maker's official page rather than relying on the listing alone. The Bluetooth version your phone and headphones support can also affect which codecs are available.

Common codec names you will see

Listings for wireless headphones sometimes name a codec as a feature. Common examples are AAC, aptX, and LDAC. These are different codec families used for Bluetooth audio. Which one a listing chooses to mention may depend on the maker's target audience.

For example, the Soundcore page lists 'Hi-Res audio refined by LDAC' for one of its earbuds. That is a codec name on a listing. If a listing does not mention a codec, it does not mean the product is missing one. It may simply support the standard codecs, and the maker may not see a reason to name them. When a codec appears on a listing, it is usually paired with other features like Hi-Res certification; see Hi-Res audio certification for what that label means.

Bitrate and latency: what the terms mean

Two technical figures often appear in discussions about codecs: bitrate and latency. Bitrate is the amount of audio data sent per second. A higher bitrate can carry more information, but it also uses more bandwidth. Latency is the delay between when a sound is initiated and when you hear it from the headphones. Lower latency matters for video and games.

Neither figure is printed on every listing. When a number does appear, it is on the maker's page, not on the listing itself. The guides on this site compare only the stated details, so they do not rank codecs by these figures. If you want to know the bitrate or latency for a specific pair, check the maker's official page. If the page does not give a number, the exact figure is not stated, and comparing it to another pair is not possible from the listing alone. For more on latency, see low latency Bluetooth codecs.

How to match a codec with your phone

The codec used for a Bluetooth connection is not chosen by the headphones alone. Both the source device, usually your phone, and the headphones must support the same codec. During pairing, the two devices negotiate and pick a codec that both support.

To get a specific codec, first check which codecs your phone supports. Many phones have a settings menu for Bluetooth developer options that lists supported codecs. Then look for headphones that list the same codec on their maker's page. If the headphones support a codec your phone does not, that codec will not be used.

Some phones change the codec automatically based on the best available option. The listing may name one codec, but the actual codec used depends on the phone. This is one reason why codec names on a listing are not a guarantee. For a broader view of the wireless connection, see wired vs wireless headphones to decide which fits your listening habits.

What to check on a listing and the maker's page

Start with the listing: look for codec names in the bullet list or the title. Words like LDAC, aptX, or AAC are clues that the maker considers codec support a selling point.

Then open the maker's official page for the model. The maker's page often lists supported codecs, Bluetooth version, and sometimes bitrate or latency figures. That is the only place to find numbers that can be compared.

Also check your phone's supported codecs. If a pairing uses a codec you did not expect, the phone may have limited support. You can sometimes change the codec in the phone's developer settings.

Finally, remember that codec support is only one part of the wireless experience. The guides on this site compare headphones on stated details like fit, battery, and noise cancelling, so a codec match alone does not decide the best pair. A codec name on a listing is not a promise of how the pair will sound; the guides never claim sound quality. Instead, use the codec name as a technical match to check against your phone. For a full list of wireless options, see the best wireless headphones guide.

What to pick for your situation

Questions

What is a Bluetooth codec?

A codec is the method used to encode audio for transmission over Bluetooth. It determines how the audio data is compressed and sent from your phone to the headphones.

Does my phone need to support the same codec as the headphones?

Yes. Both devices must support a codec for it to be used. During pairing, the devices negotiate to find a common codec.

If a listing doesn't mention a codec, does it still work?

Yes. Every Bluetooth headphone uses a codec by default, typically the standard SBC. A listing may omit the codec name if the maker doesn't consider it a key feature.

What is LDAC?

LDAC is a codec name that appears on some listings, such as Soundcore earbuds that advertise 'Hi-Res audio refined by LDAC.' Whether your phone uses it depends on support on both sides.

Can I change the codec my phone uses?

Some phones allow you to select a codec in developer settings. Check your phone's documentation to see if and how you can choose.