Bluetooth 7 will be almost four times faster, and lossless audio is next

Bluetooth comes in more than one flavor. Bluetooth Low Energy, or LE, is the sipping-power version used in earbuds, watches, fitness bands and smart bulbs. Its top speed today is 2 Mbps. That means 2 megabits, or 2 million tiny pieces of data, every second.

HDT lifts that ceiling to 7.5 Mbps. The group describes it as a leap that comes without giving up what made LE popular, which is sipping a tiny amount of battery. It is part of Bluetooth Core 7.0, the next version of the rulebook that every Bluetooth maker follows.

HDT is an optional piece of that rulebook. No company has to use it, and each maker decides for itself.

Speed comes from a new "physical layer," which is the part of the standard that decides how signals travel through the air. Think of it as a new way of packing a suitcase: the same suitcase, more clothes.

The new layer uses fancier ways of shaping the radio signal, called modulation. Instead of sending one simple bit at a time, it packs several into every signal pulse. All five HDT speeds, which are 2, 3, 4, 6 and 7.5 Mbps, use the same pulse rate. They just carry more in each pulse.

More speed usually means more mistakes, so HDT adds safety nets:

• Error correction: Extra backup bits let a receiver repair small errors without asking for a resend.
• Small blocks: Data is split into blocks, each with its own check. If one block breaks, only that block is sent again, not the whole packet.
• Speed switching: Devices can drop to a slower HDT rate from one packet to the next when the signal gets noisy.
• Big packets: A single packet can carry up to roughly 8,000 bytes in the largest mode.

In real life Say you send a photo from your watch to your phone. With old Bluetooth LE the photo crawls over. With HDT, the same job finishes in about a quarter of the time, as long as both devices have the new chip.

The group calls premium wireless audio the flagship use. Today's LE Audio uses a codec called LC3, which squeezes sound so it fits through the narrow pipe. It sounds good, but lossless audio, meaning sound with nothing thrown away, does not fit.

HDT widens the pipe. The SIG says it supports lossless and high-resolution audio, plus surround sound and spatial audio, which makes sound seem to come from around you. The group also expects earbuds, headphones and speakers to stream hi-res music in the coming years.

There is a side benefit. Because data moves faster, a device spends less time with its radio on. That can lower latency, the small delay between pressing play and hearing sound. It also means the radio can nap more often.

The SIG says yes. Sending the same data faster means the radio can return to a low-power rest sooner. Better error handling also means fewer resends, and every resend costs energy.

The group frames this as getting higher speed without paying extra in battery life. A Nordic Semiconductor executive, Øyvind Strøm, said a faster link could help a smart lock last longer between battery swaps and let earbuds stay out of their case for longer.

Audio is only the first stop. The SIG and its members point to several other uses:

• Smartwatches: Strøm described a watch that syncs hours of sensor-rich training data to your phone in seconds.
• Smart glasses: Glasses could hand more data to a phone for processing, which makes richer AI features possible.
• Smart home: A device could finish a firmware update with almost no downtime for you. That means the built-in software that runs the gadget gets refreshed in seconds.
• Health and industry: Medical and factory devices that send big bursts of data get more room to work.
• Spatial computing: Headsets and other devices that need steady, rich data streams.

The SIG also says the member community is working on other upgrades. These include high-resolution and lossless audio features, new radio bands around 5 GHz and 6 GHz, and carrying IPv6 internet traffic over LE. HDT gives those ideas the bandwidth they need.

HDT comes with security changes too. Message integrity checks, which prove a message was not changed on the way, grow from 32 bits to 64 or 128 bits. Devices can also switch to new encryption keys when they move between the old and new radio modes.

The standard supports separate keys for different kinds of links, such as data and audio. It also adds an option called opportunistic encryption, which lets two devices turn on encryption on the fly even if they never paired before. The SIG says these changes keep security up to date as speed climbs.

The Bluetooth SIG says compatible devices should reach stores starting in 2027. Premium audio comes first. There is no exact date, and no one has named the first products.

The chips are already being tested. Realtek, a chipmaker, worked with test-equipment maker Rohde & Schwarz on what they called the first HDT test setup. Realtek's Yee-Wei Huang said the feature is "a key enabler for the next wave of immersive audio and seamless connectivity experiences."

The catch: HDT is a hardware change. Your current earbuds, watch and phone will not speed up with an update. You need a new radio chip on both ends of the link. A pair of HDT earbuds paired with an older phone will still work, but at the older speeds.

New chips cost makers extra, so some may wait and watch. Apple has not said anything publicly about HDT. The SIG's chief marketing officer, Ken Kolderup, told Japanese reporters that the choice belongs to each company. He added that the group feels Apple's interest is very high, because Apple executives take part in the talks about the standard.

That is a hint, not a promise. Earbuds only get the full benefit when the phone supports it too, so the phone makers matter a lot here.

• Do not rush to buy: Nothing you own gets faster, and the first products are a year away.
• Look for HDT on the box in 2027: Earbuds and headphones with lossless sound are likely to lead.
• Check your phone, too: For the best speed, both the phone and the earbuds need the new chip.
• Expect small wins first: Faster firmware updates and quicker syncing will show up in watches and smart home gear.