How Can I Tell If My Internet Is Being Throttled by My ISP?

Currently, the easiest way to determine if your Internet Service Provider (ISP) throttles your internet speed is to run a speed test and then install a Virtual Private Network (VPN) and run the speed test again. If your internet is significantly faster with your VPN than without it, your ISP is likely throttling your service.

A VPN basically creates a privacy wall around your network that your ISP can’t see into. The good news is that a VPN can also keep ISPs from throttling your service. But, to understand how, you must first understand the differences between throttling and other types of slowing in your internet connection.

internet speed test button

Why do internet speeds slow down?

If you notice your internet connection working more slowly than usual, the cause is likely one of three issues.

1. Your provider’s network is experiencing high traffic levels.

Internet connections function like roadways for digital information, and just like real roadways, they can run into slowdowns and traffic jams. These slowdowns can stem from your ISP’s network or your home network.

If a lot of people in the same area are online, the data they’re sending back and forth can max out the network’s bandwidth and cause slowing. If this occurs, it’s usually in highly populated areas during peak hours on evenings and weekends. You can use this guide to determine if your home network is the source of your slow internet or if it’s slowing down before it gets to your home.  If the slowing is happening on your ISP’s network, call customer service and ask if they can boost speed in that area.

If the slowing is happening on your home network, you might need more speed to handle your internet activities. Before you get a bigger plan, first find out how much internet speed you need.

How much speed do you need

2. Your equipment is jammed.

This is the most common reason your network slows down. Modems and routers can end up receiving more information than they can handle. When this happens, your network slows down or even freezes. Usually resetting your modem or router will clear out the data traffic jam and get your network back up to speed. If this happens often, you may want to find a better router.

3. Your provider is throttling your connection.

Internet throttling is the act of purposely slowing down internet service. This is usually done by Internet Service Providers, but in some cases an internet user may want to throttle their own service.

For instance, if you have a data cap on your internet service, you might want an internet-limiter tool to throttle your internet to conserve data.

The natural slowdown in internet speed that can occur from high traffic levels on a network is not considered throttling. However, if an ISP deliberately slows down one customer’s internet to increase the bandwidth of another customer, it would be considered throttling.

Why do Internet Service Providers throttle internet?

Your ISP may have a few reasons to throttle your internet.

1. Some internet subscriptions include a clause that allows the ISP to throttle a user’s speed if they reach a given data limit. So, if your internet slows down, you might want to see if you’re over your data cap. If you’re wondering if your ISP has a data cap, you can find out by reading our article on which Internet Service Providers have data caps.

2.  Some ISPs have been accused of throttling an internet user’s speeds based on the user’s internet activities. Although that wasn’t allowed under net neutrality laws, it still happened on occasion. In such cases, the user was often participating in high-bandwidth activities, like downloading videos via torrent files. The ability of an ISP to change your internet speed on the fly based on your activities is part of what makes throttling difficult to detect.

3. An ISP may also slow down its network at a point where it connects to another part of the internet. This may allow the ISP to persuade content providers whose traffic regularly comes through that connection to pay more for access.

Speed tests alone may not detect throttling.

If you think your ISP is throttling your service, you can try a speed test to see if you’re getting close to the speed you expect from your ISP. (You shouldn’t expect the full bandwidth advertised at all times. Your speed will fluctuate within the full bandwidth capacity of your connection. Read more about the difference between speed and bandwidth.)

Unfortunately, most ISPs have started noticing when a user initiates a speed test and stop throttling for the duration of the test. So, the speed test results look normal, but as soon as the test is done, the ISP goes right back to throttling. This is what makes a VPN your best option.

VPNs can help you detect and avoid ISP throttling.

Virtual private networks (VPNs) can inhibit your ISP from detecting what you’re doing on the internet, so your ISP won’t know when you’re running a speed test or downloading movies in torrent files.

With a VPN masking your activities, you can get an accurate speed test that will help you see if your ISP is throttling your internet. Additionally, your ISP won’t be able to throttle your internet if you’re torrenting too many videos because it won’t know when you’re doing that either.

Along with combatting throttling, VPNs can protect your privacy. Get help choosing a VPN.


What happened to Glasnost?

Developed by researchers at the Max Planck Institute for Software Systems, Glasnost was a tool that tested for internet throttling. Unfortunately, in February of 2017, internet browsers stopped supporting the Java applet that made Glasnost work.

Are there any other throttle-detection tools available?

Many big online corporations, like Google and Netflix, have their own bandwidth tests available, but unless you have a VPN, they’re subject to the same limitations as a standard speed test. has an Internet Health Test that tests internet speeds at transition points between networks. This will show you if your ISP slows down its network at a transition point to another part of the internet. This is a useful tool, but its results tell you about throttling at your ISP’s transition points to other networks, not necessarily your connection directly.

What should I do if my internet is being throttled?

Internet throttling continues to be a threat for consumers. With the recent repeal of net neutrality regulation, ISP have less oversight, so they could easily decide in increase throttling. Be prepared. Get your VPN now. If you’ve determined your ISP is throttling your internet and want to switch providers, enter your zip code to find other Internet Service Providers available in your area.

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Author -

With over five years writing about the internet industry, John has developed a deep knowledge of internet providers and technology. Prior to writing professionally, John graduated with a degree in strategic communication from the University of Utah. His education and experience make his writing easy to understand, even when covering complex topics. John’s work has been cited by, PCMag, The Washington Post, Los Angeles Times, and more.

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