Bluetooth 5.1 is the location release: direction finding with angle of arrival and departure on the LE radio, plus GATT caching and advertising refinements, and no audio codec changed. The specification page lists 5.1 as Adopted with the same 2024 amendment note across the 5.x line, and the core line has since moved to 6.x. For sound, 5.1-era devices negotiated exactly the codecs their makers licensed, same rule as every version before and after.
Figures on this page were checked September 2026. Every table row carries its source and access date.
Version facts
| Item | Value | Source / as of |
|---|---|---|
| Specification status | Adopted, Core Specification (amended) 5.1 | Bluetooth SIG spec page, 2026-09-22 |
| Amendment | Amended 2024-06-11, effective 2024-07-01, per the specification page note | Bluetooth SIG spec page, 2026-09-22 |
| Current core line | 6.x: current flagships quote Bluetooth 6.0 and v6 | This site's Xiaomi 15 and Pixel 10 records, 2026-09-22 |
What 5.1 introduced
| Feature | Domain | Source / as of |
|---|---|---|
| Direction finding (AoA / AoD) | LE radio location | Core Specification 5.1 summary of changes, 2026-09-22 |
| GATT caching enhancements | Connection efficiency | Core Specification 5.1 summary of changes, 2026-09-22 |
| Advertising Channel Index | LE advertising channel updates | Core Specification 5.1 summary of changes, 2026-09-22 |
What it means for audio
Nothing here touches a codec. Direction finding is a location feature, and the caching and advertising refinements are bookkeeping. A 5.1-era headphone link negotiated the same codec families as a 5.0-era one, and the version-to-codec independence the 5.0 page documents holds unchanged. The audio-relevant release of the era arrives with 5.2.
A "Bluetooth 5.1" badge on a headphone or receiver describes its radio generation, not its sound. Check the codec list on both ends, the [Xiaomi](/compatibility/xiaomi) and [iPhone](/compatibility/iphone) records show how differently makers fill that list on the same versions.
FAQ
No codec changed in 5.1. The release is about location, direction finding on the LE radio, and connection bookkeeping; Classic Audio kept its machinery. Sound quality on a 5.1-era device tracked the codec both ends negotiate, as on every version.
No. Codec availability follows the device's codec set and licensing, not the core version: our device pages show the same codec families on 5.0-era and 5.3-era hardware, and iPhones stay within AAC and SBC on every version.
Direction finding, angle of arrival and departure, the headline feature, plus GATT caching improvements and advertising channel index updates. Feature names per the core specification's summary of changes, verified at fact-check.
[Bluetooth 5.2](/compatibility/bluetooth-5-2), the version that actually touched audio's foundations with LE isochronous channels, the basis of LE Audio and Auracast. The full line now runs to 6.x on current flagships.
blafili B3 Bluetooth Receiver
XLR, RCA, optical and coax outputs with an OLED front panel, built on the QCC5125 + ES9018K2M platform. A wired amp or receiver, put on a wireless source.
- Bluetooth SIG, Core Specification (amended) 5.1, Adopted; mandatory specification updates and the 2024-06-11 amendment note verbatim on the page. bluetooth.com/specifications/specs/core-specification-amended-5-1/, accessed 2026-09-22
- Bluetooth SIG, Core Specification 5.1, summary of changes: direction finding (angle of arrival and departure), GATT caching, advertising channel index (feature names verified at fact-check against the specification document's summary of changes, §10.1). Accessed 2026-09-22
- Current-version context, this site's verified pages: Xiaomi 15 lists Bluetooth 6.0, Pixel 10 lists Bluetooth v6. Accessed via our Xiaomi and Pixel profiles, 2026-09-22