Bandwidth throttling: What it is, how to test for it, and how to stop it

What is bandwidth throttling?

ISPs can throttle bandwidth for legitimate reasons, such as managing congestion on their networks or maintaining fast speeds for users on high-tier plans. They may start throttling your bandwidth when you get close to your data cap — the limit of the total amount of data you can use each month. However, in some cases, your ISP could throttle your bandwidth even if you have a plan with unlimited data. 

Common types of bandwidth throttling 

Network bandwidth throttling can happen in several scenarios. The most common types of bandwidth throttling include:

• Congestion-based throttling. ISPs throttle users during busy times of day to prevent network congestion. 
• Data-cap throttling. ISPs place monthly data limits on users. When you hit that limit, your internet speed drops. 
• Application- or service-specific throttling. ISPs throttle customers using specific apps or services, such as video streaming or gaming platforms. These services use significant bandwidth, so ISPs can throttle them to manage network load and avoid network jitter. 
• Prioritization of higher-tier customers. Some ISPs provide faster service for users with higher-level plans and throttle everyone else on the network. Consumer advocacy groups have raised concerns that ISPs partner with specific services to give them “fast lanes” and throttle their competitors.
• Mobile deprioritization. Cell phone carriers temporarily slow your data speeds when you’re in a crowded area. 

In some cases, ISPs use deep packet inspection (DPI) to inspect your internet traffic and throttle bandwidth based on specific activity types, such as online gaming or video streaming. This strategy is rare, as it is expensive and time-consuming for ISPs to implement. However, when it does happen, it’s a significant invasion of privacy. 

Why do ISPs throttle your bandwidth?

ISP throttle bandwidth for several reasons: 

• Congestion management. During peak evening hours, web traffic increases, which puts strain on an ISP’s infrastructure. When traffic in a certain area gets too high, ISPs throttle nearby users to prevent congestion. 
• Lowering operating costs. High-speed internet networks are expensive to operate. ISPs often throttle users to keep their operating costs down, especially if users participate in high-bandwidth internet activity. Many ISPs and mobile providers implement data caps for the same reason. 
• Revenue incentives. In areas without net neutrality laws, services could pay ISPs to prioritize their traffic. For example, a streaming service could pay an ISP for faster speeds. In this scenario, if you spend a lot of time on Netflix while your ISP has “fast lane” contracts with Disney+, your Netflix connection will likely slow down.

In many cases, ISPs only throttle specific activity types. If you don’t use a VPN, what your ISP can see includes websites you visit and when you visit them. Your ISP can use this information to determine when to throttle you. 

Mobile bandwidth throttling

Throttling isn’t limited to your desktop computer — it’s common on mobile devices, too. In fact, you’re more likely to get throttled by your cell phone carrier than your ISP due to strict mobile data limits. 

Many cellular carriers throttle your traffic once you pass a monthly data threshold, even on an unlimited plan. Some carriers also have video resolution caps, which prevent you from watching videos in HD when you use cellular data. 

You may also experience traffic deprioritization when you’re in a busy area. This is when your carrier slows your mobile data speeds to prevent network congestion. 

If your mobile carrier throttles specific traffic types, like video streaming, you can use a VPN on your mobile device to hide your activity from your provider. However, if your mobile carrier has strict data caps, a VPN won’t help you get around them. A VPN affects data usage, too. It consumes a small amount of additional data to encrypt your connection and route it through a VPN server, but it shouldn’t send your monthly bill skyrocketing. 

How to run a bandwidth throttling test

If you think your bandwidth is being throttled, you can run a bandwidth throttling test to check your internet connection and speed. 

Here’s how to run an internet health test for bandwidth throttling: 

1. 1.Run a baseline speed test. Open your preferred speed test platforms and run a speed test to check your download and upload speeds. Run the test at least twice with different tools for accuracy. Note down the results.
2. 2.Repeat the test at different times of day. Run the test a few more times at different times of the day. This test can help you determine whether the throttling is due to peak-time congestion. 
3. 3.Repeat the test during different types of online activity. Run the test during different types of online activity, especially high-bandwidth ones like gaming or streaming. This test can help you identify whether your ISP throttles specific types of traffic. If you notice buffering or slower speed, connect to a VPN and run the speed test again. For best results, connect to a nearby server — proximity minimizes the speed loss from a VPN. Note down the results for connection with and without a VPN.

4. Compare the results. 

If your internet speed is slower during a particular time of the day, it could be a sign of ISP throttling bandwidth to prevent network congestion. 

If your internet speed is significantly faster while connected to the VPN, it could be a sign that your ISP throttles you based on your activity. A VPN can help you avoid this type of bandwidth throttling.

Is bandwidth throttling legal?

In most places, bandwidth throttling is technically legal. Many ISPs rely on bandwidth throttling to manage network traffic and prevent disruptions. 

However, bandwidth throttling is at the core of the net neutrality debate in the United States and many other countries. In 2015, the US FCC introduced the Open Internet Order, which made throttling, paid prioritization, and blocking web access illegal. However, the order was repealed in 2017. 

In 2024, the FCC voted to restore net neutrality laws, only to have federal courts strike down the order in 2025. As of 2026, net neutrality is no longer legally mandated at the federal level. However, many states either have already adopted or are in the process of adopting their own net neutrality regulations. The most notable of these is the California Internet Consumer Protection and Net Neutrality Act of 2018. 

How to stop bandwidth throttling

Bandwidth throttling is frustrating, but you can try a few things to stop or manage it: 

• Upgrade your plan. If you’re hitting hard data caps, upgrading to a higher-level plan is usually the easiest way to get faster speeds. 
• Monitor your data use. If you can’t afford to upgrade, try to save some data throughout the month so you don’t get throttled. 
• Contact your ISP. If you’ve tried upgrading your plan and still aren’t getting results, get in touch with your ISP to find a solution. 
• Switch to a new ISP. If throttling is interfering with your daily routine and your current ISP isn’t improving, consider switching to a different ISP that can provide more reliable service. 
• Switch from mobile data to wired broadband. If you’re experiencing mobile data throttling, try connecting to a wired broadband connection whenever possible to save data. 
• File an FCC complaint. If you’ve tried everything and you’re sure your ISP is throttling you, consider filing an FCC complaint as a last resort. 
• Use a VPN. If you’re experiencing activity-based throttling, use a VPN to encrypt your traffic. If an ISP can’t see what you do online, it’s harder for it to throttle you based on specific activity. 

Can a VPN help with bandwidth throttling?

Yes, a VPN can help with bandwidth throttling, but only if your ISP targets specific types of online activity. That’s because a VPN encrypts your traffic so your ISP can’t see what you do online. For example, if your ISP is throttling specific streaming services, your VPN will prevent it from seeing which streaming sites you use. Instead of seeing which sites you visit, your ISP only sees your connection to a VPN server. 

For best results, use a high-speed VPN designed for reliable performance. NordVPN’s NordLynx protocol — its proprietary implementation of WireGuard® — and extensive server network offer consistently reliable speeds and privacy from your ISP. 

However, a VPN won’t fix every form of bandwidth throttling. A VPN won’t help if your ISP is throttling everyone during peak congestion hours or if you’ve hit a hard data cap. 

Quick speed improvement tips

If your internet is consistently slow, try these quick tips to boost your performance. These tips can improve many speed issues, not just bandwidth throttling. 

1. 1.Use NordLynx. When you’re connected to NordVPN, choose this protocol for the fastest performance. 
2. 2.Connect to a nearby VPN server. The closer the VPN server is to you, the less speed you’ll lose with your internet connection. 
3. 3.Use a wired connection instead of Wi-Fi. Wired connections typically provide faster speeds. Switching to Ethernet is easy if you can’t upgrade your plan to increase bandwidth. 
4. 4.Restart your router. A restart clears the router’s memory, refreshes its connection to your ISP, and can resolve temporary glitches that slow performance.

What else can a VPN do? 

The benefits of a VPN go beyond avoiding activity-based throttling:

• A VPN encrypts your traffic, which hides your online activity. It increases your privacy online and helps protect against hackers and snoopers. You can learn more about what information a VPN hides on our blog.
• Connecting to a VPN server changes your IP address and virtual location. It improves your privacy and reduces online tracking. A VPN also allows you to compare prices when shopping to avoid dynamic pricing and lets you access the content you’ve paid for at home while traveling. With NordVPN, you can connect to servers around the world.
• NordVPN’s Dark Web Monitor scans the dark web for your leaked credentials and alerts you to breaches so you can change compromised passwords. Dark Web Monitor Pro™ offers extended monitoring of additional personal assets like credit cards and national IDs.
• NordVPN’s next-generation antivirus is a comprehensive digital threat protection tool available for Windows and macOS with selected NordVPN plans. It helps you avoid malware and scams and blocks intrusive ads and trackers as you browse online. Pages may load faster, too, since the next-gen antivirus stops ads and trackers from consuming bandwidth. Learn what next-gen antivirus is and how it works in our whitepaper.