Is Your ISP Throttling Your Data?

Is Your ISP Throttling Your Data - Blog Post

I work online. I know that right after school lets out in my area until early evening, my internet is just horrible. As a consequence, I try to get my work done before these supposedly “high traffic” times. But what if too many users were not the issue?

What if my internet service provider was deliberately slowing down my speed so that I would upgrade to a higher cost package? Knowing that might be enough to motivate me to change my provider. Is your ISP throttling your data too?

What is ISP Throttling?

ISP throttling is also known as bandwidth throttling or traffic shaping. Whichever term you use, this is the process of intentional speeding up or slowing down of internet service by the ISP (internet service provider). It is meant to minimize bandwidth congestion and regulate network traffic.

Throttling is often used in internet applications to spread the usage load over a more extensive network or servers. A system administrator could throttle bandwidth on a local area network (LAN) to reduce server crashes and limit congestion.

The ISP may use bandwidth throttling to reduce a user’s usage of bandwidth. It actively limits download and upload rates for specific programs, including video streaming, file sharing applications, and BitTorrent protocols.

Bandwidth throttling is also applied to speed up the internet when you test it on a speed test website, which seems a bit dishonest, in my opinion. Throttling can be used by internet companies to give you a reason to upgrade to a higher, more expensive package that does not throttle the bandwidth.

How is Throttling Done?

Any computer network is made up of servers. Servers provide services to clients and host data. The internet consists of web servers that are used to host websites. The websites, in turn, provide information to a large number of computer users.

These computer users, or ISP clients, make requests to the servers. The servers respond by sending the requested data, a video, Wikipedia page, business website, or song file, for example. There are many clients per server. So the data processing demand on a server is more than just one client.

The traffic on the network varies. Sometimes the requests exceed the capacity of the system, causing congestion, just like the road you dive during rush hour. At times, there is so much congestion on a server that it gets bottlenecked, and the system crashes.

To prevent bottlenecks, the administrator or ISP throttles the bandwidth to control the number of requests that the server responds to during a specific period. When the server reaches the limit, it will offload new applications, adding them to a queue, which will be processed once the bandwidth usage drops below the threshold. At times, there are so many requests in the line that the system discards them.

ISPs use deep packet inspection (DPI) to process and sort data being sent over the network. DPI can respond to the request, re-route it, or block it entirely. The data is typically sorted into a fast or slow lane based on the amount of bandwidth the application needs to run.

Fast lane examples:

  • Web-browsing
  • Social media
  • Google

Slow lane examples:

  • YouTube
  • Hulu
  • Netflix
  • BitTorrent
  • Twitch
  • WoW
  • League of Legends
  • Fortnite
  • Usenet
  • RDP

As the data is being inspected with the DPI, internet service providers can collect information on traffic flow to throttle bandwidth during peak hours. ISPs claim this is to ensure that everyone has better quality service, not just high bandwidth users that watch videos or upload and download torrents.

However, the truth is ISPs use bandwidth throttling to serve more clients without increasing their network capacity, which increases the profit margin. This seemingly underhanded practice is entirely legal since the Net Neutrality law was repealed.

How Can You Tell if Your Internet Service Provider is Throttling Your Internet?

If you notice any of the following tell-tale signs, your ISP is throttling your internet.

  • Consistent slow internet speeds
  • Slow speeds during specific hours.
  • Slow speeds while loading or watching YouTube videos.
  • Slow loading speeds and buffering when using Netflix, Google Play or Hulu.

Running a speed test is not enough to tell if your ISP is throttling your bandwidth. Remember, I mentioned that throttling occurs when you try to test your internet by using a speed test site, which will give you inaccurate results.

Most throttling happens at the protocol level. Therefore, your overall bandwidth may not change, but your video streams at a lower resolution, for example. There are a few online test sites that can help you determine is your ISP throttling your data or not.

Check out:

  • The Internet Health Test
  • Network Diagnostic Tool
  • BISMark
  • MobiPerf

The Internet Health Test is a free app developed by FightForTheFuture. It can check your internet performance to see if there are any readily noticeable bottlenecks.

M-Lab Tests include the Network Diagnostic Tool, BISMark, and MobiPerf. The Network Diagnostic Tool can test your connection speed and provide you with a diagnosis of issues that are limiting it. BISMark applies a host to your home router and over time, tests network performance. MobiPerf gauges network performance on your mobile devices. is a test designed by Netflix, one of the companies most affected by ISP throttling practices. It uses Netflix data to determine whether your internet is being throttled.

How Can You Reduce ISP Throttling?

There are two great ways to work around ISP throttling. They are:

A Virtual private network (VPN) encrypts all the internet traffic from and to your device. The encryption prevents the ISP from seeing what protocols, websites, and services you are using. Since the ISP can’t determine what you are using, then it can’t separate the traffic into a fast or slow lane.

A VPN generally incurs a monthly fee, but if your ISP is being substantially throttled during hours when you want to use it, it would be worth it. When choosing a VPN, look for one that:

  • Has lots of server locations
  • Doesn’t keep logs
  • Has DPI prevention
  • Supports P2P and torrenting

The more server locations a VPN has, the better it is for your potential internet speed. If the nearest location is saturated, things will slow down. Being able to switch to another place that isn’t too far away with fewer users will keep things trucking along nicely.

The VPN should also not keep logs. The reason you are using a VPN is for privacy from ISP spying. If the VPN goes and sells your information to an ISP, then what’s the point? The two other things to look for are DPI prevention and compatibility with torrenting services.

A Seedbox is a remote server that has high-bandwidth. It is used to download or upload digital files from a P2P network. If you do a lot of torrenting, this might be a good, but pricey way to get around ISP throttling.

For what it’s worth, EarthLink Internet is now advertising that their internet is never throttled. Perhaps more internet service providers will take note and join implement this marketing strategy in the coming months.


Is your ISP throttling your data? Most likely. Internet service providers reduce bandwidth access during peak traffic hours. Streaming sites are the most affected. Although it seems like shady business, bandwidth throttling is enitrely legal.

If you suspect that your ISP is throttling your data, then test your theory with one of these:

  • The Internet Health Test
  • Network Diagnostic Tool
  • BISMark
  • MobiPerf

Once you’ve established that yes indeedy, there is throttling going on, then work around it with a VPN or Seedbox. There’s no reason to be held back by the man when it comes to your internet habits.

Blair Campbell

Founder of GetInternet. Blair studied computer science at the California Institute of Technology Computing and Mathematical Sciences program, but he enjoys writing on the side. He grew up in southern California and now lives in Denver, Colorado.