Why Does Broadband Speed Fluctuate? And How to Fix it

why broadband speed fluctuates and how to fix it

Look at 99% of ISP marketing and they all drone on about speed-this and speed-that as their top offering. Without a doubt, speed should be on the list of things to consider, but it shouldn’t be top of the list.

Your broadband speed affects the length of time taken to upload and download your files, images and videos. It facilitates movie and audio streaming as well as virtual meetings, VoIP and helpful instructions to turn left at the next corner before. But most people ask why does broadband speed fluctuate? And how to fix it? That is why stability is important – and should be at the top of the priority list.

A survey of the C-suite, by the International Data Corporation (IDC), revealed 60% of businesses have prioritised edge computing solutions ‒ and it’s not for speed reasons; it’s to stabilise latency and avoid fluctuations.

That’s a lot of terminologies squashed into a few paragraphs, so let’s start at the beginning.

What is broadband?

The “always-on” service of sending data of a particular size (wide bandwidth) via an internet connection through coaxial or fibre-optic cables, Wi-Fi, DSL or satellite is defined as broadband. The term “wide bandwidth” refers to frequencies between 50–7,000 Hz. This frequency type is important for facilitating superior quality audio and visuals for gaming, streaming, etc. 

Some internet agencies stipulate that a broadband connection must offer:

  • 25 Mbps (megabytes per second) download speed
  • 3 Mbps upload speed

The type of technology you select for your personal, business or community connections will be influenced by the user needs and preferences and, in some countries, by cost. If you live in an outlying area, the infrastructure investment cost may prohibit the setting up of hardware from bringing a connection to your location.

why broadband speed fluctuates and how to fix it

What is fibre optic?

Fibre optic cables are made up of a combination of layers. Fibre optics cables are comprised of:

  • A core
  • Cladding
  • Kevlar®
  • Ferrules
  • Connectors

The component referred to as the ‘core’ is super-thin glass as thin as human hair. Data is transmitted in the form of light pulses. 

A vital part of the fabrication process is the polishing of the core, which affects the efficiency or effectiveness of data transmission. Top-quality cables can transmit data at 940 Mbps.

What is wireless?

A wireless connection is also called Wi-Fi. This type of connection is used in houses, offices, hospitality venues, etc. It utilises radio signals ‒ not cables ‒  and can offer speeds of 300 Mbps.

What is DSL?

The acronym DSL stands for digital subscriber line. This type of connection uses standard copper phone lines to transmit data at speeds up to 15 Mbps.

Cable & Satellite

A cable connection uses coaxial cables with high-speed transmission.

As per its name, a satellite connection transmits via dedicated satellites and is a great option for difficult to reach, outlying areas.

What broadband speed should you select?

There could be as many answers as there are users. For example, do you stream movies or love gaming? Are you a film editor who downloads and uploads massive files? 

For regular sending and receiving of huge files, it would be prudent to consider a 100 Mbps connection as this would also reduce the risk of latency. 

If you are an avid movie streamer or WFH and do frequent virtual meetings, then a 25 Mbps connection will suffice.

Why is broadband speed fluctuation a problem?

The speed of the connections we listed above is inconsequential if they fluctuate like a yo-yo. You can miss a deadline or waste hours in the office. Stability means more effective work and a more enjoyable movie experience, for example. You can do online research without having to make a cup of tea while each new website opens. 

A broadband speed that fluctuates does not necessarily mean you have a bad connection. It could indicate a ‘traffic jam’. A massive customer, e.g. a bank, might have mistakenly done a huge data dump onto the connection at peak hours which will have a widespread impact on other users. 

Regular traffic jams indicate another possible issue. So why does broadband speed fluctuate? And how can you fix it?

Can internet stability be tested?

If your broadband speed fluctuates regularly, use the below checklist to ascertain if any of these scenarios relate to your situation:

  • Do websites suddenly take ages to open?
  • Do your files upload and download well sometimes, but go into a holding pattern on other days? Even with small files?
  • Do your Skype or Zoom calls suddenly pixelate and freeze out of the blue? Then burst back into life?
  • Do websites load but only in parts? And then do different parts of the site load in a staggered, ad hoc manner?
  • Does video streaming buffer some days and not on other days?

If these scenarios sound like something that you have experienced, your broadband speed fluctuates. 

You can test your internet stability, and it is quick to do. Checking it regularly is a good idea and gives you an opportunity to advise your service provider or rectify the problem before an important task or event is affected. 

You can go to our testing tool for help.  Run the test, which is super quick and informative, to get your download, upload, ping and jitter result. The “Ping” and “Jitter” answers are the ones to take note of. If the numbers are high, this indicates that your connection may have fluctuation issues. If the Ping answer is above one hundred, this should be a red flag. The Jitter answer should have a number that is lower than thirty. A number that is higher than that could be an indication that your broadband speed is fluctuating. 

why does broadband speed fluctuate and how to fix it

Actions to take when broadband speed fluctuates

There are a few steps you can take when you suspect that your broadband speed is fluctuating. 

Background Apps

Step one: Check if there is anything that could be impeding your home or office connection. An impediment could come from bandwidth-hungry applications running in the background, or too many applications running in the background. Shut down unnecessary apps like Skype if you are not using them. Skype is a fabulous communication program, but it is data-hungry. Outlook is also data-hungry. Set a time to check emails, e.g. once every two hours and then open outlook at that time.


Unfortunately, it could also mean there is a nasty virus that has ducked under your security software and is working its way through your software.  If you don’t have anti-virus or anti-malware software, you should buy some urgently. For the amount of protection they offer, there are a number of fairly priced options out there. For example, you can get a package for individuals or an enterprise package for a business team.

Next, activate a virus scan on your laptop or PC and read the results. Fingers crossed that it comes back with a clean report. 

High traffic

Some users may find that broadband speed only slows at a certain time of day, but otherwise it does not fluctuate at all. This is probably a ‘peak hour’.

Interestingly, weather can also impact broadband speed fluctuation, but so can a weak Wi-Fi signal. The latter can be solved by adding repeaters into big areas or where there are thick concrete walls or steel-reinforced interior elements affecting signal quality. 


Next, there could be an issue with your modem hardware or your external Wi-Fi-to-optical cable dish.


Last but not least, the RAM of your laptop or PC can also affect your perception of broadband speed. No matter how fast your internet connection is, if your laptop RAM or processor is old or faulty, you will not have an enjoyable uploading and downloading experience. You will also experience crashes when working in online documents like Google Docs.

What is ‘peak hour’?

Peak hour is when an unusually large amount of users come onto the network at a regular time, or one particularly large user does a huge data transfer at a regular time, thereby affecting general speed for thirty minutes, for example.

The peak hour can also be created locally. It does not necessarily mean that the customers of your service provider are all jumping onto the network at the same time. An example of a localised peak hour would be when the kids come home from school, you and your partner come home from work and you all want to access audio-visual files online at the same time. That is a very high-bandwidth demand and, like a peak hour vehicle traffic jam, so too your digital road gets jammed with data “cars” or parcels. So no matter if you have a Lamborghini internet connection, if there are too many vehicles on the road, you will just have to chug along.

Digital traffic is difficult to solve, especially if it is only for short periods. It doesn’t make financial sense to upgrade to a bigger connection if you need 1 hour a day solved. You could plan your big file work at times that do not conflict with peak hour or download audio-visual files off-peak to watch offline. 

Slow or incomplete web pages

When you are browsing, your internet software tries to help by storing log-in details or copies of pages so that when you return to these pages, they will load faster. This is your cache data. What can happen, however, is that over time you can build up a huge amount of cache data, which then affects the speed at which your software can process things.

Your web browser might have become cache-heavy, and thus the experience is sluggish and frustrating. Go to your web browser menu and find the ‘Clear Cache’ option. A regular clean up will help your laptop or PC speed relating to web usage.

In addition, remember that websites communicate via thousands of different servers worldwide connected via diverse networks. These servers and networks each have their unique speed and capabilities. Another factor is the methodology, software and correctness of the build of a website. Do you remember when Flash websites were super popular? A Flash homepage was usually slow and problematic because of its bandwidth needs. If an important site, for you, runs slowly, then try to plan its usage during off-peak hours.

The impact of weather

Most people think we’re nuts when we suggest that weather might influence broadband speed fluctuations. Inclement weather can and does affect the quality of your broadband connection. If you are on a Wi-Fi connection, then the impact of this factor is amplified even more. 

Unfortunately, unless you are Zeus, you will need to wait for the troublesome weather to pass before getting a good connection back. Alternatively, you can also pull out that rarely used cable (if you can remember where you have carefully stored it) and connect your laptop or PC Ethernet port via cable to your modem. This will improve stability and speed.

Wireless signal strength

Sometimes you may think you have a fluctuating broadband speed but what the problem is, in fact, is a Wi-Fi signal that needs boosting or a repeater. 

Homes, offices, restaurants and hotels are filled with walls, reinforced concrete beams, embedded steel, etc. In addition, commercial and retail spaces often have lots of other electrical pathways and equipment such as sound systems, heating systems, communication systems, security systems, etc. These can all create electrical interference and hinder the strength of your Wi-Fi signal.

A booster or an extender (repeater) might be the solution as well as ensuring that your computer cables do not run through the same conduits or power skirting as other electrical cables. Electrical cables do not, as everyone believes, have electricity running through the middle of them. Instead, electrical cables carry fields of electricity that circulate around their exterior. That means that the fields interact with any cables next to them, including data cables. 

Hardware issues

The next thing to consider is the actual hardware you are using and their installation setup. Do a visual and physical check of your modem, router, all the cables and their connection points, as well as your laptop or PC. 

If your hardware is old, it may be a bottleneck. It doesn’t have to be damaged to be a problem. Hardware made two years ago might not have the capacity to handle the larger, more complex files or transactions that cutting-edge software demands. 

Modems, routers, cables, laptops and PCs all need to be replaced regularly to cope with ever more sophisticated software and processes.

You can also check the firmware and see if an upgrade is available. For example, check if your laptop or PC has the capacity for a memory upgrade, a processor upgrade, a graphics card upgrade, or you might need a total replacement.

If someone has “meddled” with your modem cables and switched them, then you will definitely encounter issues. The cable may just have been bumped during a cleaning day of the office which will cause connection hiccups. Even if a visual inspection indicates that everything is in order, do a physical check, as a slight misalignment can cause many hours of frustration. You can also try swapping ports as ports also age and need replacing.


If you have worked through this checklist and still do not know why your broadband speed fluctuates, please immediately call our helpful technical support team. Remember our motto:

Whoever, wherever –

we connect communities

When you call to raise an issue, we are all ears, and we quickly jump into action to resolve it. 


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