Technology Explained

Li-Fi Is 100x Faster Than Wi-Fi, But What’s the Catch?

Mihir Patkar 06-12-2015

You’ve heard of Wi-Fi, now you need to hear about Li-Fi. Still in the nascent stage, this new technology could change how you use the Internet. It’s much faster than existing Wi-Fi tech, it’s more energy-efficient, and potentially more secure as well.


But of course, there are just as many downsides.

Li-Fi, or Light Fidelity, is suddenly in the news these days because an Estonian company called Velmenni conducted a real-world test where it was able to transfer data between devices at 1 Gbps, which is roughly 100 times faster than Wi-Fi in the real world. In lab tests, the fastest recorded speed was 224 Gbps!

And it all works with the simple power of light.

What Is Li-Fi?

Li-Fi’s biggest proponent is Harold Haas, a professor at The University of Edinburgh, and founder of the company pureLiFi, which is trying to bring the technology into real world markets.

Li-Fi is dependent entirely on light, specifically LED bulbs. In a way, it’s the next step in connected lighting What Is Connected Lighting & What Are Its Uses? The Internet of things is upon us, and its next victim is your household light bulb. Read More . In the simplest terms, Li-Fi transfers data over light waves. By comparison, Wi-Fi uses radio waves.


This means that Li-Fi is completely wireless, much like existing Wi-Fi. Haas also stresses that it can operate with existing LED bulb technology. Note: “existing technology” doesn’t mean “existing LED bulbs” that you already have set up in your house. Li-Fi actually works on wireless protocols much like Wi-Fi’s 802.11.

In short, you’ll need new bulbs. Li-Fi will also require a new piece of technology in your smartphones and laptops: a photosensor. Photosensors (also called photodetectors) are sensors which can “read” incoming light.

How Does Li-Fi Work?

Li-Fi works much like the infrared technology in your television, and infrared works on a simple principle: an input command is given (e.g., “change channel” when you press a button) and that input is turned into binary code What Is Binary? [Technology Explained] Given that binary is so absolutely fundamental to the existence of computers, it seems odd that we’ve never tackled the topic before - so today I’d thought I’d give a brief overview of what binary... Read More .

That code is then transmitted over infrared light waves by your remote’s sensor, and the light waves are received by your TV’s infrared sensor, which decodes the light and performs the intended input action.



PureLiFi’s infographic above shows how this works. The Internet and router/server is hooked to a cable, and the cable is attached to any number of LED bulbs in your house. The LED bulbs then transmit the data as modulating light waves while a photodetector on your phone or laptop picks up those light waves and decodes them.

So anywhere that your LED bulb is casting light that your photodetector can “see”, you’re ready to get Internet access — and at speeds faster than Wi-Fi.

Howevenr, this means that Li-Fi requires direct line-of-sight between the source (bulb) and recipient (phone or laptop), so while properly configured Wi-Fi can go through walls Wireless Feng Shui: How to Optimize Wi-Fi Reception in Your House Setting up a Wi-Fi router for optimum coverage isn't as easy as you think. Use these tips to cover your whole house with Wi-Fi! Read More , you won’t be able to do that with Li-Fi.


What Makes Li-Fi So Promising?

Watch the demo above and you’ll see the huge potential of this technology. There are some obvious benefits over Wi-Fi:

  1. You won’t have to worry about congested radio waves and wireless dead zones What Is a Wireless "Dead Zone"? Here's How to Spot and Fix Them Wi-Fi can suffer interference and obstructions. Learn how to spot and fix wireless "dead zones" or "dead spots" in your home. Read More .
  2. It’s much, much faster than existing Wi-Fi speeds.
  3. It’s more energy-friendly than Wi-Fi, which requires power-hungry masts. Also, if your photodetectors are solar cells, as Haas envisions, you might be able to use wireless battery charging What Is Wireless Charging & How Exactly Does It Work? [MakeUseOf Explains] We live in a wireless world. Except we don’t. Sure, we can send huge amounts of information across the airwaves, but the devices capable of sending and receiving it are tied down to power cords.... Read More and wireless Internet simultaneously.
  4. Li-Fi’s direct line-of-sight requirement means that it’s probably going to be more secure than Wi-Fi, since someone outside your home can’t hack into your system. But, as Techcrunch points out, a telephoto lens and optimally tuned photosensor could potentially change that.

The Problems With Li-Fi


While all of this sounds really good, there are some major problems that Li-Fi still has to overcome:

  1. Li-Fi cannot be used in direct sunlight (or other odd conditions with harsh lighting) since the photodetectors won’t be able to detect the modulating light waves. It’s unclear what counts as a poor condition, but as Velmenni’s and Haas’s demos have shown, it does work with some amount of ambient lighting.
  2. The line-of-sight requirement can be a major bottleneck. Let’s say you have one Li-Fi bulb in your living room and you want to move to your bedroom. Well, you better have another Li-Fi bulb set up there or you’ll be out of luck.
  3. Li-Fi is going to need reinvestment in lighting and wiring infrastructure.

Will Li-Fi Revolutionize the Internet?

Right now, it’s honestly too early to tell. Advocates of the technology suggest that instead of Li-Fi replacing your existing setup, it’ll be an additional connectivity source that boosts your usage. PureLiFi illustrates this by showing how you are likely to go from LTE to Wi-Fi to Li-Fi in your home:



We probably won’t see a mass rollout of Li-Fi anytime soon. PureLiFi is the leader in this regard and has so far joined up with one French company to hopefully go to market by the third quarter of 2016.

What Does All of This Mean?

The bottom line for you right now? Nothing changes.

Li-Fi seems like really cool technology and could help augment existing Wi-Fi and other wireless connectivity — it could potentially even replace it altogether — but actual usage for us consumers is a long, long time away.

Until that happens, check out Haas’s most recent demonstration of Li-Fi and be amazed by what the marriage of LED bulbs, Li-Fi, and solar cells could bring to our smart homes of the future:

What Do You Think About Li-Fi?

What’s your take on this new wireless tech, is it the future or just a fad? Would you buy into Li-Fi technology any time soon?

Related topics: Computer Networks, Wi-Fi.

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  1. Martin Seebach
    December 30, 2018 at 7:25 am

    Very cool with many areas for use. I'm not too sure about in home consumer but anywhere the setup is planned to reduce or eliminate blockage it has some pretty awesome potential. Great outside thinking. Use in conjunction with parallel charging puts the icing on.

  2. ololo chukwuemeka bright
    July 1, 2018 at 6:12 pm

    kindly help me with lessons and details involved in creating the digital LiFi internet setup and its configuration to the pc or phone

  3. Vinesh V
    June 7, 2016 at 5:16 pm

    Thanks alot for this information. From my point of view, your article is unique because you raised the negative side of the LiFi technology, which has provided me more insights of this technology.

    • Steve Starkey
      April 27, 2017 at 3:59 am

      I disagree. The true "negative side" has not been raised. The LiFi technology is only showing one direction (download) communication. What about uploading? Before the LiFi system can deliver the desired material, your request for that material still needs to go out. Also, a LiFi connection will not speed up your ISP. You will not get a LiFi promised 1Gbps download if your ISP connection only delivers 50mbps to your location.

  4. Sophie Franklin
    April 22, 2016 at 7:21 pm

    It looks brilliant. At the moment we are using a dongle and we feel so independent of all the heavy internet traditional connection, we can't wait to get LiFi

  5. Navaneeth K M
    April 7, 2016 at 3:19 pm

    Please try to explain how to make Li-Fi at home!!!

    • This guy->
      August 10, 2016 at 9:23 am

      U don't make it when it comes into use company's like BT will sell stuff like fittings, bulbs and new hubs that allow u to use lifi and wifi it will come with a free installation or a manual.
      The article says that our phones and tablets will have to have built in recivers but that will not be necessary when on the go as in one of LiFi's videos they showed how you could plug in a reciver.

  6. Gerry
    February 5, 2016 at 3:27 am

    My opinion is mixed as I don't know how to get the service is it expensive?, A lot of unanswered questions so can't form a definite opinion. Who is issuing this service? , Who can you contact?

    • This guy->
      August 10, 2016 at 9:27 am

      Look it's not on the market yet and it may never be so calm down and continue with your life and you will know when lifi is available.

  7. Tom Sawyer
    January 26, 2016 at 7:31 pm

    How does the signal get to my house? Cable? electric wires? Light?

    • This guy->
      August 10, 2016 at 9:29 am

      It will get there the same as wifi and you won't need to worry your wifi company will screen at you ween lifi is available.

  8. Ben
    January 19, 2016 at 6:29 pm

    Perhaps devices, particularly mobile devices, could transmit their signal via the screen itself. That might address the issue of power consumption, since the idea is to use a source of light already being utilized. Though, I must admit, there are still serious limitations in my mind that it would not address: How does it work when the screen does not immediately face the receiver, and how you would distinguish that signal from other sources of light or how is it possible to clearly transmit a signal in a dynamic environment with many other user devices transmitting their own photoelectric signals?

  9. David
    December 22, 2015 at 1:42 am

    So we're going to be eventually see internet in terms of Gigabytes per second, rather than the Megabytes per second we do now? How very... predictable. I remember thinking of internet in terms of Kilobytes per second; in fact, I still do when on a particularly slow connection. Heck, my parents probably remember the days of thinking of connections in terms of Bytes per second.
    Everything, and nothing, speeds up as technology advances. Websites will simply continue to increase the amount of data required to load them. My mother remembers the days when one could reliably stream a YouTube video on Dial Up!

    • Mihir Patkar
      December 22, 2015 at 7:57 am

      Well yeah, progress is inevitable, but the cool thing here is a different direction for the same predictable progress, right?

  10. srinivas
    December 17, 2015 at 5:43 pm

    I have an idea, why can't we have LiFi LED bulb inside the device. However, we can use Lifi where ever we go.

    • Mihir Patkar
      December 22, 2015 at 7:58 am

      Probably because it would take more battery, and there would be physical limitations right now. But we might see your idea manifest in the future! Nice lateral thinking, srinivas :)

    • James
      January 10, 2016 at 2:06 am

      Exactly what I was thinking! Inside the device would be a photodetector, directly next to a LiFi LED Bulb, except miniature scale. And battery life? Well, you could always chuck in a Super Capacitor.

      Super Capacitor link here:
      LiFi link here:

    December 13, 2015 at 2:45 pm

    I want the design of receiver circuit in last video please any one

  12. Paul
    December 12, 2015 at 8:41 pm

    Receiving light from the bulb is all well and good, but how do I send data back upstream? Do I now need to attach a light to my computer? And a receiver to my household lamp?
    Doesn't sound like a particularly useful technology...

    • Mihir Patkar
      December 22, 2015 at 7:59 am

      Good question! I'll look into it.

      • Will
        December 25, 2015 at 11:40 pm

        I believe I had read that you would need a special receiver (USB connected) that would also act as a transmitter, at least for desktop computers. As for a smartphone, I suppose it would be the same idea, plug an additional attachment, but unfortunately most probably would also shorten the battery life. The problem I see with this is as with other techologies is the speed you get from your ISP. Sure, on your LAN you could have a Gazillion Bytes Per Second, but if you only have a connection with your ISP at 2-3Mbps, that Gazillion bps won't be of much help. Still, the faster even though locally the better. Maybe in a more mature form, this could be a great technology, but we'll have to wait to see how it evolves.

    • Dickson
      January 25, 2016 at 5:51 pm

      I have the same concern as you Paul, communication between devices is a two way street which means a device must be capable of receiving information and transmitting it as well. So my guess is that in order for a phone to transmit data it must have a led bulb on every time we want to use this technology and that I believe would be annoying for most of all.

  13. Prabeesh
    December 11, 2015 at 4:52 am

    In case of an office's desktop it's much useful i think.. May be new tech will come for connecting the light receiver to any high speed switches so we can extend the speed..

    • Mihir Patkar
      December 22, 2015 at 8:00 am

      Oooh that's interesting.

  14. suraj kumar
    December 11, 2015 at 3:53 am

    it's better for only some devices like tv.but if we are talking about phone then it's not more useful

    • Mihir Patkar
      December 22, 2015 at 8:01 am

      Why not for phones, Suraj?

  15. Anonymous
    December 11, 2015 at 2:12 am

    The obvious answer is to use LiFi as a redundant connection asset. We do this Bluetooth and NFC so why not here, at least until it finds its niche or is proven a flawed concept. I, for one, would gladly give it a try.

    • Mihir Patkar
      December 22, 2015 at 8:01 am

      Makes total sense!

  16. Anonymous
    December 10, 2015 at 5:52 pm

    So it's basically useless if my phone is in my pocket. Right now wi-fi penetrates my jeans pocket and sends data to my phone; whereas for this to be useful I'd have to have my phone sit out on my desk all the time.

    I can see the appeal of a dedicated point-to-point data connection for stationary devices such as TV's, access points, hubs, or other connected devices that remain stationary; however, this becomes useless when you have mobile devices that do not always face the same direction with a photosensor always pointing at a bulb. For high-bandwidth devices like a smart tv streaming data, this can be great, but for phones, not so much.

    • Mihir Patkar
      December 22, 2015 at 8:02 am

      The "phone in pocket" is a pretty great example of a failing of LiFi, Shawn! I hadn't thought of that :)

  17. Tushar Shah
    December 10, 2015 at 8:09 am

    WHy people forget that if LI-FI has to work, u need to conatantly Switch ON your bulbs, IT MEANS MORE ELECTRICITY & ENERGY to be used.
    HEre v r tlking abt conserving energy/electricity & to use net u hv to once again waste/use electricity ?
    Re-think this plssss..........

    • Mihir Patkar
      December 22, 2015 at 8:02 am

      It's an add-on tech, Tushar, not a replacement for WiFi. And it's LED, so it's more energy-efficient than a regular bulb.

  18. Anonymous
    December 10, 2015 at 6:28 am

    You know, I probably wouldn't use this because I usually download large files overnight while I sleep. And sleeping with the light right next to you is not a good idea.

    • Mihir Patkar
      December 22, 2015 at 8:03 am

      You won't need the light on, the real-world application is that even the light coming in through the bottom of your door would be enough. And they might be able to do dimming/colors in light too.

  19. Blacksmith
    December 10, 2015 at 1:10 am

    I hope it works more efficiently than Infra Red did. I had an IR channel changer in the 70's. Yes, it could change the TV channels at a press of a button, but if I rattled my car keys when I came in the room it also change the channels!! Much to my children's annoyance!

    • Mihir Patkar
      December 22, 2015 at 8:03 am

      This is my big worry too! I hope it's better than IR.

      December 22, 2015 at 2:52 pm

      You might be confusing IR technology with Ultrasound. IR remotes could never be confused with rattling keys. Ultrasound remotes had aluminum slugs inside that emitted an Ultrasound each time the were struck by a button. All the human would hear was a click, each time the button was pressed thereby generating the term "clicker" for a TV remote. :)

  20. will2b
    December 8, 2015 at 4:45 pm

    what if you dont want the light on whilst watching porn?

    • Dale
      December 8, 2015 at 9:30 pm

      Since nobody wants their lights to flash on and off anyway, it would probably use infra-red frequencies of light, so a dark room would be ideal.

      • Rahul
        December 10, 2015 at 8:46 am

        In Order to over come the light swithing on and off problem.
        Can't We Fix The sensor which predict the light and comapre with darkness and once the sensor threshold reaches above the darkness level we can able to fix the system in order to swith the light in black colour which won't effect the Humans.

      • Ray
        December 22, 2015 at 3:03 pm

        Just as a point of fact, currently your lights DO flick on an off, ALL AC lights do. They flick on an off at a rate of 120 cycles per second (CPS or Hz) here in the USA. We use 60 Hz as our electrical standard, we get 120 Hz because each cycle is made of of two zero crossing points, thus any light that is driven by household current WILL flicker at 120hz. Ever notice how annoying those LED Christmas lights are? Since they are "solid state" lighting they have nothing to keep glowing during the zero crossing point. With incandescent lamps the filament is still hot and continues to glow during the zero crossing point, even florescent lamps continue to glow during this point due to the phosphors in the tube, that is why we don't notice the flicker. This is called persistence. If the frequency was high enough you never would see the flicker

    • Mihir Patkar
      December 22, 2015 at 8:06 am

      Hahahhaa nice one

  21. Ray
    December 8, 2015 at 2:39 pm

    Very NICE. (sarcastic) One way communication link, seems like a half-baked idea. Let me know when its a total solution.

    • Mihir Patkar
      December 22, 2015 at 8:04 am

      It's about the future, Ray, but I get your apprehension :)

  22. Gary Story
    December 8, 2015 at 12:55 pm

    Not much to say one way or another about it yet. LIFI has possibilities as another option that can be used in certain situation. I just had to say I Love jeff Thomas's reply!

    • Mihir Patkar
      December 22, 2015 at 8:04 am

      Yeah, same here!

  23. Frank
    December 8, 2015 at 5:47 am

    Isn't this just the same as fiber optics, except there is no fiber optic cable?

    • Mihir Patkar
      December 22, 2015 at 8:05 am

      I don't see how it's similar, Frank. Care to elaborate?

  24. Arnold Ziffel
    December 8, 2015 at 3:18 am

    Wait a minute..When did all this happen? Wifi? huh? Lifi? who?
    None of this will improve my Radio Shack Color Computer.
    Technology .Feh !

    • Mihir Patkar
      December 22, 2015 at 8:06 am

      I'm just going to throw this idea out there, but maaaaaybe it's time to upgrade, Arnold.

  25. Ken
    December 7, 2015 at 9:47 pm

    This demos how the data is transferred from the light to the phone. How does your phone respond? When you click a link for example the phone has to transmit the request back. Does this mean that this would be one way and some thing else used to send the request.

    • Terry
      December 8, 2015 at 1:46 pm

      That's exactly what I was wondering??? This would only be downstream. What about upstream? Do you always have to have the lights on to have this work, or will the data wavelengths continue even though you turn off the visible light?

    • Mihir Patkar
      December 22, 2015 at 8:07 am

      It does work, but I need to look into how it works. I'll get back to you on this :)

  26. Anonymous
    December 7, 2015 at 5:18 pm

    Hello, all.
    Light can be harmful; Ever get sunburned, or have your eyes 'flashed' by a welder?
    How about the effects of flashing lights?
    We already have far too much EMF radiation, w/ the known & unknown effects.
    What 'side effects' will this tech have?
    It sounds good,
    but I have to agree w/ Mr. Borsos; It looks like overkill, and in the wrong medium, too.
    Line-of-sight can be very limiting, until more is known about "LiFi,"
    not much chance we'll see it soon.
    Have a GREAT day, Neighbors!

    • Yohan
      December 7, 2015 at 8:22 pm

      I'm not too sure if you know about led lights.
      Have you ever seen the little lights on Christmas trees?
      Yeah i don't think of any scenario where an led light can blind someone as much as getting a sunburn, or the flashes of a welder. And even if you're eyes are that sensitive to light, you can apply a filter on it as well. The radiation emiting from the bulb is the exact same as the regular radio waves of youre average wifi. Harmless. If you're going to go on about radiation, and you live anywhere near a city, the city will do you more harm than a little led light.

  27. Anonymous
    December 7, 2015 at 2:40 pm

    What if someone has a window in their Li-Fi active room, simply by training a detector from outside on that window you'll be able to pick up the data. It's true it is probably encrypted, but encryption can be broken...So all you'll need now to pick up the data from far away is a decent telescope and a free encryption hacking program.

    • jeff Thomas
      December 8, 2015 at 10:20 am

      I like it "a decent telescope" the technology is not out and we have the first lifi hacker

  28. Pedro
    December 7, 2015 at 6:52 am

    Great job

  29. Daniel Borsos
    December 6, 2015 at 10:26 pm

    Communication speeds that exceed SATA 3 are not useful in a home environment. A slower version would be useful for replacing USB with a wireless solution on mobile devices, but I can't imagine using it like a router for 2 way communication. That would mean a "blinking" bright omnidirectional lightsource on my laptop.

  30. Roger Caldwell
    December 6, 2015 at 8:22 pm

    Just what I want...the ability to burn through the battery on my phone or tablet even FASTER! Take this technology out behind the barn and shoot it!

    • Anonymous
      December 8, 2015 at 12:21 am

      "Take this technology out behind the barn and shoot it!"
      Too late! The horse is already out of the barn.

    • Charlie LaCross
      December 9, 2015 at 12:02 am

      How is download speed going to affect battery use? Don't be a fuddy-duddy, you silly man.

      • Roger
        December 9, 2015 at 2:11 am

        It has to transmit also, requiring a lot of light generation. Don't be myopic.

        • ololo chukwuemeka bright
          June 20, 2018 at 4:40 pm

          what is responsible for amplification and processing of electric current converted by the photodetector in the LiFi internet set up
          kindly respond quickly
          more so i want to know if a WiFi modem can be used to amplify and process the detected electric current by the photo detector into data.
          also is it necessary adding the WiFi modem on both end since i can just plug my LED lamps directly to light