What Is A Fast Internet Speed?

Fast is a relative term.
Fast for 1 person or 100 sharing the connection?
Fast for a big city or fast for a remote location?
Fast for home or fast for a football stadium with 100,000 WiFi users
Do the variables above make any sense ?  It was only meant to tell you that “fast” speed is not a clear figure but it is measured relative to other factors depending on circumstances and time. In the 1990s, we were amazed when we first got 256 kbps; in 2006, we was delighted with 2 Mbps, and now we are unhappy with “just” 10 Mbps

Why?

Because in 2006, we wanted to download the 4 GB installation of Half-Life 2 through the 2 Mbps connection; in 2017, we want to download the 50 GB installation of DOOM (2016) through the 10 Mbps connection. So even though our connection is 5 times  faster, our experience is actually 2.5 times slower.
So it not  unfair to assume that in 2025, we will be unhappy with the 100–250 Mbps fiber optic cable connection and will envy the South Koreans and thei 1 Gbps fiber optic connections. And DooM (2024) will require 500 GBs, probably 🙂
Nevertheless, 10 Mbps is often cited as the break-off point between slow and fast internet, because it allows things like “Watching full HD streams from YouTube”.

How is internet speed measured?

Internet speed is measured by how much data the connection can download (download speeds) or upload (upload speeds) per second.
For most households, internet download speeds are what’s important. That’s what we use for common activities such as streaming TV, downloading music and browsing social media.
Upload speeds come into play with things like video conferencing and uploading large files to a server or cloud. Check out this blog for more information about download vs. upload internet speeds.
In both speed types, the speed is shown as bits per second (bps). Since an internet connection transfers thousands of bits per second, we use the prefixes k, M and G to show how many thousands of bits we’re talking about. If you’re familiar with the metric system, you know “k” = 1,000, “M” = 1,000k (1,000,000), and “G” = 1,000M (1,000,000,000).
When coming across internet speeds, you’ll likely see Mbps more than kbps or Gbps. That’s because Mbps speeds are more suited to what we use the internet for.

Speeds that fall into the kbps range are generally what we’d call “slow” internet, and Gbps speeds, which are rare but becoming more common, are in the ultra-fast range.

What is considered fast internet?

Internet download speeds of 100 Mbps or higher are often considered fast internet because they can handle multiple online activities for multiple users at once without major interruptions in service. If you need a little help determining what speeds you need for your intended internet use, we’ve got you covered.

Common internet speed tiers considered fast include:
100 Mbps
200 Mbps
250 Mbps
300 Mbps
400 Mbps
500 Mbps
1,000 Mbps
2,000 Mbps

Cable and fiber-optic internet services are your best bet for fast internet speeds. Fiber-optic internet is also a great choice for speed consistency, as it is less vulnerable than cable to slowed speeds during peak usage times.
Popular cable or fiber-optic internet providers include: AT&T, CenturyLink, Cox, Frontier FiOS, Optimum, Spectrum, Suddenlink, Verizon Fios, XFINITY and Windstream. Many of these providers offer speeds up to 940-1,000 Mbps in select areas, but XFINITY is currently the only provider with speeds up to 2,000 Mbps.

Internet Speed Factors:

Several factors affect your internet access speeds:

Your Access technology
Your ISP
Location of the remote resource
Time of Day
Internet Access Technology

This is the most important factor as far as internet access speed is concerned.
All technologies have limitations. The connection speeds of fiber broadband is far superior to 3G mobile.
See common Internet access methods. for an overview with pros and cons of each technology

Your (Internet Service Provider) ISP:

You connect to your ISP (using an access method e.g. ADSL Broadband) and your ISP then connects to the Internet.

ISPs advertise the connection speeds to the subscriber, and not the speeds between the subscriber and the Internet.
In the UK the connection to the home is almost always a BT phone line and ADSL, but fibre is becoming increasing popular.If that is the case then The access speed will be limited by these BT lines regardless of the ISP you choose.
However that doesn’t mean that all providers will provide the same overall connection quality as-.
The connection between the ISP and the Internet is usually over fiber and is fast, but it is shared by many subscribers.
Therefore if the ISP overloads the link to the Internet it slows the connection from subscriber to Internet.
So your Connection to the ISP could be 6Mbits/s but from you to the Internet it could be only 3 Mbits/s.
Here is a quote from the BBC article on broadband speeds

Almost half of broadband users are now on packages with advertised speeds above 10Mbps but the average broadband speed is 6.8Mbps according to Ofcom.

The Location Of The Service/Server On The Internet:

The Internet comprises a vast network on interconnected computers and networking equipment e.g routers (diagram below).


The number of routers/servers that the data must travel through on the way to and from the destination service/server will affect the overall speed.
In addition the speed and capacity of the network that inter-links these computers/routers will also affect the final connection speed.

In general the Internet itself will often be the limiting factor that affects your overall internet speed.

So you may have a super fast connection to the Internet, but still take the same amount of time to download a file from the Internet as someone with a much slower Internet connection.

Time of Day:

You may have noticed that the Internet appears to slow at certain times of day.
This is very similar to rush hour on the roads.
Here is a uswitch graph showing Internet speeds in the UK over the day.

Notice how the average speed drops from almost 10Mbps to around 6Mbps
The worst time to be surfing the net is between 7pm and 9pm.