We’ve all heard the rumors, and even seen occasional evidence. Some Internet service providers slow down certain types of traffic, like BitTorrent traffic. Other ISPs slow down their customers’ connections if they download too much data in a month.

But does your ISP do any of this? It’s hard to tell. You have to run various tests to see if anything look unusual.

BitTorrent Traffic Shaping

Let’s start with one of the more common scenarios: is your ISP slowing down your BitTorrent traffic? Or are your torrents just slow?

Neubot is a useful tool for testing BitTorrent traffic shaping and monitoring it over time. This tool is a bit complicated to use, but is rather powerful.

To install it, visit the Neubot page and click the “Windows” link. Download and install it like any other program. Neubot will run in the background and automatically perform tests. To view the Neubot web interface, open your Start menu and click the “Neubot” shortcut.

After opening the Neubot interface, click the “Privacy” tab, allow the options under Privacy dashboard, and click “Save”. This gives Neubot permission to collect and publish your Internet address on the web for research purposes. If you don’t want to do this, you can’t use Neubot.

This data provides a picture of traffic shaping on different Internet service providers across the Internet, and collecting it is the reason for Neubot’s existence.

To manually start tests, select “speedtest” from the Manually start test box and click “Go”. Neubot will perform a standard HTTP speed test.

Next, select “bittorrent” from the Test box and click “Go”. Neubot will perform a BitTorrent speed test.

As with other similar tests, you’ll want to run this test while you’re not performing any large downloads on your network.

Click the “Results” tab at the top of the page to view your results. From the Test box at the top of the page, select “speedtest” and click “Go!” to see your HTTP speed test results.

Then, select “bittorrent” from the Test box and select “Go!” to see your BitTorrent test results. Compare the speeds shown on the two different pages.

Take the results with a grain of salt. As the Neubot interface says, “[the bittorrent] test is quite different from the speedtest one, so there are cases where the comparison between the two is not feasible”. Just seeing a difference between the two speeds doesn’t mean much, especially if you’ve only ran a single test for each.

However, if BitTorrent speed is extremely low compared to HTTP (speedtest) speeds, there’s a good chance your ISP is throttling your BitTorrent traffic. In the screenshots here, the speeds are actually very similar and we don’t see any throttling.

This tool runs in the background and runs tests automatically, so you can leave it installed and check in now and again to see how the results fluctuate over time. If you don’t want Neubot to run, you can uninstall it from the Control Panel just like any other program.

The Glasnost project once provided web-based tests that could identify whether different types of traffic are being rate-limited (slowed down). However, this tool was shut down in 2017.

Bandwidth Limiting

Is your ISP slowing down your connection because you’ve used too much data? Some ISPs have been known to do this as a way of enforcing their bandwidth caps. Even ISPs that offer “unlimited” connections may throttle you after you hit a certain, usually large, threshold.

To test whether your ISP is slowing down your Internet connection over time, you’ll have to measure your Internet connection speed over time. For example, if your ISP is slowing your Internet speed down, it’s probably slowing it down towards the end of the month after you’ve used a large amount of data. You then probably have typical, fast speeds at the beginning of the next billing period.

You can monitor Internet speed variations over time by using the SpeedTest website. Run a test at the beginning of the month and run further tests regularly, especially at the end of the month. If you consistently see slower speeds near the end of the month, it’s possible that your ISP is throttling your bandwidth. You can sign up for a SpeedTest account to log your results and compare them over time.

Note that other factors can also affect any type of speed test results. For example, if you or any other person on your network is downloading or uploading on your connection, the measurement may not be accurate—you should perform a speed test while your connection isn’t being used. The time of day can also impact your Internet connection speeds. You may see faster speeds at 3 a.m. when no one is using the shared line to your ISP rather than at 9 p.m. while everyone else in your neighborhood is using the line.

It’s also normal if you don’t see the maximum speeds your ISP is advertising. Most people aren’t getting the Internet speeds they’re paying for.

This isn’t a perfect test. An ISP could prioritize traffic from SpeedTest so that you look like you have a fast connection, even if they’re slowing your other traffic. But if you see a pattern, it may be indicating a throttling situation.

Netflix and YouTube Throttling

You may also want to try the Netflix FAST speed test. Netflix created this test to allow you to check whether your ISP is throttling connections to Netflix or not. Compare the results to the speed you see on SpeedTest. If the Netflix speed test results are significantly slower, that’s evidence your ISP is throttling

Google also provides a “Google Video Quality” report which will show the quality of your connection to YouTube’s servers. If you have a fast Internet connection but a poor quality connection to YouTube’s servers, that’s evidence that your ISP may be throttling YouTube connections.

Interconnection Issues

When you connect to the Internet, your traffic travels through your Internet service provider’s network before it leaves your ISP’s network and travels over another provider’s network. ISPs may sometimes degrade performance at these interconnection points unless the other provider pays an additional toll to the ISP.

The Internet Health Test by Battle for the Net checks your Internet connection to see if there are problems at “interconnection points”. By checking a number of different routes, the tool will detect whether you’re experiencing degraded performance at one or more interconnection points.

The tool performances a number of different speed tests across different networks. If all of them are fast, you’re not experiencing this problem.

If your ISP is throttling your connection, there’s not much you can do, unfortunately. You can switch ISPs and try to find a better one—assuming your ISP doesn’t have a monopoly in your area. You may also be able to pay for a more expensive plan with higher bandwidth allocation and, hopefully, without traffic shaping.