On November 4, 2026, the Bluetooth SIG announced the adoption of a new high-speed communication technology, Bluetooth High Data Throughput (HDT). An optional feature added to Bluetooth Core 7.0, it raises the maximum bit rate of the Bluetooth Low Energy (LE) physical layer (PHY) from the 2Mbps of the current LE 2M to 7.5Mbps. This opens the possibility of transferring larger amounts of data in less time while keeping the power-saving design of Bluetooth LE.
The Bluetooth SIG's "roughly fourfold speedup" compares the maximum speeds of the physical layer, which carries bits over the air. Strictly speaking, it is a 3.75x increase (7.5 ÷ 2). The speed actually available to applications is affected by control information, retransmissions, and other overhead, so file transfers will not simply become about four times faster. In addition, HDT support and communication at 7.5Mbps are separate conditions: both devices must support the required speed and transmission direction.
How HDT reaches up to 7.5Mbps in the same 2.4GHz band
HDT's defining feature is that it raises speed while using the same 2.4GHz band as conventional Bluetooth LE, with no change to channel width or channel spacing. Rather than widening the radio bandwidth, it improves spectral efficiency, carrying more information in the same bandwidth.
According to the technical overview published by the Bluetooth SIG, HDT has five speed modes, and the symbol rate is fixed at 2Msym/s (2 million symbols per second) for all of them. The symbol rate indicates how many times per second the state of the radio signal changes. HDT leaves this rate unchanged and instead increases the number of bits carried in each symbol: π/4 QPSK represents 2 bits, 8PSK represents 3 bits, and 16QAM represents 4 bits.
The actual bit rate is not determined by the modulation scheme alone, however. HDT combines forward error correction (FEC), which lets the receiver correct data errors, with puncturing, which omits part of the error-correction code, to achieve the speed of each mode.
Even during high-speed transfers, the control header at the start of a packet uses the comparatively robust π/4 QPSK. This lets the receiver correctly identify the modulation scheme and speed of the data that follows, and the speed of the data portion can be changed packet by packet. A "Link Quality Feedback" mechanism for notifying the other side of communication quality is also provided. It is an optional feature, though, so not every HDT-compatible device will necessarily select the best speed automatically based on conditions.
To transfer large amounts of data efficiently, an optional packet format called "PF1" is also introduced. PF1 can send up to four payloads together, and each payload can be further divided into 1 to 16 blocks. Each block is checked with a CRC (cyclic redundancy check), and selective retransmission resends only the portions in which errors occurred. Sending multiple pieces of data together reduces the share taken up by control information, and because an entire packet need not be resent when an error occurs, transfer efficiency is expected to improve. PF1 itself is optional, however, and HDT products will not necessarily adopt it.
HDT support does not guarantee 7.5Mbps
In Bluetooth Core 7.0, implementing HDT itself is optional. Even devices that adopt HDT need not support every speed. The five modes defined by the Bluetooth SIG and their requirements are as follows.
| Mode | PHY bit rate | Modulation | Requirement when HDT is implemented |
|---|---|---|---|
| HDT2 | 2Mbps | π/4 QPSK | Mandatory |
| HDT3 | 3Mbps | π/4 QPSK | Mandatory |
| HDT4 | 4Mbps | 8PSK | Mandatory |
| HDT6 | 6Mbps | 16QAM | Optional |
| HDT7.5 | 7.5Mbps | 16QAM | Optional. HDT6 is also mandatory if supported |
A controller that implements HDT must support the three modes HDT2, HDT3, and HDT4. HDT6 and HDT7.5 are optional, and a device that supports the top speed of 7.5Mbps must also support 6Mbps. In other words, a label saying "HDT-compatible" alone does not mean a device can communicate at 7.5Mbps.
More importantly, the requirements differ between transmitting and receiving. At each rate, transmission is optional even for a device that supports reception. Conversely, a device that supports transmission at a given rate must also support reception at the same rate. As a result, a device that can receive at 7.5Mbps cannot necessarily transmit at that speed. To use high-speed communication, the transmitter's sending capability and the receiver's receiving capability must match in the direction actually being used.
Compatibility with existing Bluetooth LE devices is also maintained. The connection is established using the conventional PHY with GFSK modulation, and if both sides support HDT, they switch to a high-speed mode. If the support conditions do not match, the conventional PHY can still be used, so introducing HDT does not immediately make communication with existing devices impossible. However, HDT requires new radio circuitry, so an existing device that supports only GFSK cannot be made HDT-compatible through a software update alone.
Prototype hit about 3.8Mbps, but short transmissions can backfire
How much speedup can be expected in real data transfers? In a technical article dated October 29, Nordic Semiconductor published the results of a demo using two HDT-capable prototypes. The test transferred 2MB of data using a 508-byte payload in a normal office environment.
According to Nordic's approximate figures, the fastest HDT mode averaged about 3.8Mbps, with a transfer time of about 4 seconds. Conventional LE 2M averaged about 1.4Mbps and took about 12 seconds, while LE 1M averaged about 0.76Mbps and took about 22 seconds. Compared with LE 2M, HDT delivered roughly 2.7 times the average transfer speed and about one-third the transfer time. These are manufacturer demos at the prototype stage, however, and do not guarantee the performance of mass-produced products, speeds in crowded radio environments, or speeds when connected to a smartphone.
Nordic also notes that HDT may be slower than LE 2M when sending short packets. When the amount of data is small, the fixed overhead from headers and other control information and from processing becomes relatively large, so the advantage of the higher physical-layer bit rate cannot be fully exploited. Conversely, applications that transfer large amounts of data continuously benefit more from the higher speed.
This difference also explains why it matters that the conventional PHY remains available. Exchanging small amounts of data with low latency and sending large files in bulk call for different approaches. The headline figure of up to 7.5Mbps should not be taken to mean that every kind of Bluetooth communication will improve.
High-quality wireless audio is slated for standardization in 2027
In its official announcement, the Bluetooth SIG names high-quality wireless audio, which it plans to standardize in 2027, as HDT's first flagship use case. HDT is positioned as a foundation for transmitting lossless and high-resolution audio, as well as spatial and multichannel audio.
This does not mean, however, that the release of any particular earbuds or smartphone is assured. Nor will every existing LE Audio product support HDT. At this point, the name of any new audio codec, as well as specifics such as sound quality and latency, have not been disclosed. The adoption expands wireless transmission capacity, but putting it to use for high-quality audio will require standardization of the audio specification and the development of compatible products.
Beyond audio, the Bluetooth SIG envisions applications in wearables, AI-equipped devices, smart home devices, and more. The examples it cites include syncing workout records on smartwatches, sending data for processing from smart glasses, and updating firmware on smart home devices. For uses involving relatively large amounts of data like these, shorter transfer times translate directly into a better user experience.
On the power-saving side, transferring the same amount of data in less time could let the radio return to a low-power state sooner. However, no specific battery life figures for HDT or power-consumption comparisons with conventional methods have been presented. How much the speedup contributes to a product's overall power efficiency will depend on future implementations and testing.
With HDT's adoption, Bluetooth LE has evolved into a standard that can handle fast transfers of large amounts of data in addition to conventional low-power communication. The top speed of 7.5Mbps is optional, however, and real-world performance will vary with the supported modes, the transmission direction, and the nature of the data being transferred. Attention now turns to the real-world transfer speeds of compatible products, and to how far the standardization of high-quality audio planned for 2027 will drive adoption of the technology.