What are the differences between each version of Bluetooth?

Alex Kidman
Oct 21, 2024
Icon Time To Read6 min read
// From Scandanavia to the latest Samsung Galaxy smartphones.

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Bluetooth is in just about every gadget you buy, from smartphones to game consoles, watches to trackers.

But what is it – and what are the differences between each version of Bluetooth you might come across?

What is Bluetooth?

Pros, cons and how it works
Bluetooth speaker pairing with phone

Bluetooth is a data transmission standard rather specifically focused on short range communications between compatible devices. First coming to market in devices in the very late 1990s, the Bluetooth Standard has evolved over time with a number of significant revisions that have changed how Bluetooth is used, though the standard idea of using radio waves for data transmission is still at the heart of every Bluetooth chip.

Bluetooth is relatively cheap and simple to implement in a product, which is a big part of the reason why it’s so widespread in consumer electronics, because the cost of implementing it is relatively low. More modern versions of the Bluetooth standard offer lower power consumption and faster and more reliable connectivity between devices, but even in the earliest revisions Bluetooth was built around the concept of “pairing” devices together so that they could share data.

So when you connect up your smartphone to your wireless headphones you’re creating a paired connection between them to send and receive data – in this case, audio that you want to listen to from your phone, or commands such as play/pause or voice data from your buds to your phone for pausing music or answering phone calls. 

Why is it called Bluetooth?

Bluetooth gets its name from King Harald “Bluetooth” Gormsson (or Blåtand if you want to be pedantically specific about it), a Danish king who united the people of Norway and Denmark back in 958. 

Why King Harald, though? Largely because the original designers of the standard were companies that were mostly Scandinavian, that’s why. Harald was known as “Bluetooth” due to the presence of a dead tooth in his mouth which went blue/grey, but while that’s all kinds of gross, the idea here is that just as King Harald united the Scandinavian tribes under a single banner, Bluetooth unites devices under a standard communications protocol.

Fun trivia

Bluetooth was more or less a holding pattern name until something more catchy could come along, with “PAN” (Personal Area Network) being the favoured frontrunner – but it was found to already be a tad too generic in usage in the late 1990s, so Bluetooth more or less stuck as the official name as it caught on too fast for an alternative name to be adopted.

Is Bluetooth just another form of Wi-Fi?

No, not exactly. While both Bluetooth and Wi-Fi are data transmission standards, and both can operate around the unregulated 2.4Ghz radio bands, they are different technologies, overseen by different consortiums and essentially with slightly different markets in mind. Wi-Fi typically has higher power usage but in return works at significantly higher data rates than Bluetooth is capable of, as it was originally intended to be a wireless replacement for physical ethernet cables. 

That’s why you use Wi-Fi most likely for your home Internet, because it can handle data quickly, and it doesn’t matter as much about power if the Wi-Fi router is plugged into a wall socket anyway. Bluetooth uses lower power and shifts data at lower rates, making it a better match for lower-power intense activities that might be more mobile, such as Bluetooth headsets or game controllers.

Bluetooth 1-5: What do the numbers mean?

If you check the Bluetooth specifications for a given Bluetooth compatible device, chances are you’ll see a number after the word Bluetooth. It could be Bluetooth 4.2. It could be Bluetooth 5.3. What’s the difference?

The Bluetooth standard has evolved over time, and the suffixes after Bluetooth indicate which standard a given product was built to comply with. Any Bluetooth compliant product has to adhere to at least one level of the standard, though some cheaper products don’t always make it clear which Bluetooth version they’re actually suitable for – and if you buy some particularly cheap Bluetooth devices online you may find some less-than-reputable-brands aren’t always honest about their specific Bluetooth compatibility either!

The reality for many Bluetooth revisions is that while they improved the general performance, reliability and in some cases power usage of Bluetooth, the differences are more of interest if you’re an electronics engineer than an everyday consumer. Here’s a quick rundown of the differences between Bluetooth versions, and why they might matter to how you’d use a given Bluetooth product. Some of this is honestly more historically interesting than arguably relevant unless you’ve held onto Bluetooth devices for some decades, mind you.

Bluetooth 1 (1998)

The OG Bluetooth standard that started it all… though, honestly, in the early days the going was quite rough trying to get Bluetooth devices to properly talk to each other. Later revisions, especially Bluetooth 1.2 greatly improved matters, especially relating to interference with the introduction of adaptive frequency hopping. Bluetooth 1 is by modern standard not fast, maxing out at a theoretical 721kbits transmission speed.

Bluetooth 2 (2004)

Bluetooth 2 saw the introduction of a real boost in transmission speeds, with the core 2.0 version adding Enhanced Data Rate (EDR) specifications for improved data rates.  Bluetooth 2.1 built on this with a more secure methodology for pairing Bluetooth devices called secure simple pairing. Prior to this if you wanted to pair Bluetooth devices it had to be via a PIN code, and most opted for very low security models. Ever paired your phone to an older car with Bluetooth? The odds are very high that the pairing code was 0000, and the lack of secure simple pairing is why that was so.

Bluetooth 3 (2009)

The Bluetooth 3 specification once again saw technical changes that allowed for more reliable and faster connections, up to a theoretical 24Mbps connection if you have a Bluetooth 3 HS (High Speed) device specifically, though with those higher transfer rates came a significant leap in the power needed for data transmission.

Bluetooth 4 (2010)

The big advance (at a consumer level) for Bluetooth 4, aside from the expected boosts in speed and reliability was the introduction of Bluetooth Low Energy. Rarely has a suffix so truly encapsulated what a technology does quite so well as Bluetooth Low Energy, because, you guessed it, the key factor here is a class of Bluetooth devices that require truly tiny quantities of power to operate as very simple Bluetooth devices. If you’ve ever used a tracking device such as an Apple AirTag, the underlying technology that allows it to work at all off a coin battery is the Bluetooth Low Energy standard introduced in the Bluetooth 4 specification.

Bluetooth 4 (and some of its later point releases such as 4.1 and 4.2) is also where specific consumer-friendly features such as improved audio for speech, more secure connections and support for Bluetooth connected smart home appliances starts to come into play.

Bluetooth 5 (2016-Present)

If you’re buying a Bluetooth device right now, the odds are very good that it’ll be Bluetooth 5 compliant.

Bluetooth 5 brought with it indoor positioning specifications – again, this is how devices like an AirTag can be “found”, because part of the Bluetooth 5 specifications allows for more precise locations as part of a transmission.

Bluetooth 5.1, introduced in 2019 brought that location accuracy down to the level of centimetres from metres, while also improving audio quality and data transmission range and security.

Bluetooth 5.2 is (at a consumer level) mostly an audio level improvement with the introduction of LE Audio, allowing better quality audio and critically audio that required much less power for transmission than the classic Bluetooth audio profiles did.

2021’s Bluetooth 5.3 further improved stability and security, while the most recent iteration,

Bluetooth 5.4 added features such as enhanced security and an electronic shelf label profile – quite literally a shopping standard for goods on a shelf to advertise their pricing and features over Bluetooth. See, it’s not just about your headphones after all!

Which version of Bluetooth do I need?

Can I use older Bluetooth devices with newer ones?

Need is relative, but for the most part at a consumer level, the detail to remember is that Bluetooth is backwards compatible, so older Bluetooth devices can be seen and paired to newer ones.

However, that does entail using the oldest specification in the pairing stack, so if you pair a set of Bluetooth 4.2 headphones to a Bluetooth 5.3 capable smartphone, all you’d be getting would be Bluetooth 4.2 style performance.

Need is also relative to what you want to do with a given Bluetooth device. For most headphones this should be a fairly automatic pairing process unless a manufacturer has some kind of very specific control system in place, typically an app you’d need to install to get access to additional features rather than a Bluetooth-specific feature, however. For devices such as trackers, however, for more precise finding you’d need to have devices that support the right level of location data transmission. 

Can I update Bluetooth on my device?

iPhone SE 2022 review pic 5

In nearly every case here the answer is no, you can’t. Some devices may be produced that allow for smaller Bluetooth updates over firmware, but that’s usually just within a given Bluetooth release version, and often it’s more of a software tweak specific to that device than an actual jump up in Bluetooth versions.

If you’ve got two devices and one of them is lacking in Bluetooth compatibility with the other, the easiest way to update them is to actually update the older device to one that’s sporting a newer Bluetooth standard in most cases.

Alex Kidman
Written by
Alex Kidman is some kind of word-generating AI from the future that somehow worked out how to sneak back in time to 1998 to start its journalism career. Across that time, including editorial stints at ZDNet, CNET, Gizmodo, PC Mag and Finder, as well as contributions to every major tech masthead, nobody has quite managed to figure out this deeply held secret. Let’s keep it between us, OK?

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