Bufferbloat Test
Test your connection under load and see how much latency increases.
The test takes about a minute and saturates your connection in both directions. Keep this tab open while it runs.
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Bufferbloat Tester
Our Bufferbloat Testing tool measures how your internet connection behaves under heavy download and upload traffic. It checks how much your latency increases under load, then gives your connection a bufferbloat grade.
Bufferbloat happens when too many packets wait in network queues during congestion. The longer they wait, the more your latency increases when your connection is busy.
This increased latency can cause lag in online games, delays during calls, and a less responsive browsing experience. The bufferbloat test helps you identify the problem so you can take steps to fix it.
How to Use the Bufferbloat Test
Follow these steps to test bufferbloat.
- Click Start Test to begin
- Keep the browser tab open while the test runs.
- The test first measures idle latency. This is your connection's latency when there is little or no network traffic.
- It then measures connection latency during Download and Upload activity.
- Once complete, review your bufferbloat grade and latency figures.
- Check the detailed statistics and activity predictions to better understand your connection.
Note: Because the test deliberately creates heavy network traffic, avoid using the connection for other bandwidth-intensive activities while it is running to get accurate results.
Notable Features of Our Bufferbloat Tester
The Bufferbloat Test includes the following features:
1. Bufferbloat Grade
It displays a simple letter grade that summarizes how well your connection handles increased traffic without causing excessive latency. Even if you don’t have much technical knowledge about networking, you can understand the results easily.
2. Idle Latency Measurement
The test measures your connection's baseline latency before the test puts your network under load to get an accurate picture of bufferbloat.
3. Download & Upload Testing
The test measures latency while your connection is handling both heavy downloads and uploads. This allows the test to measure how latency changes during both download and upload activity.
4. Latency Increase Analysis
Our test shows you exactly how many milliseconds your latency increases when the connection is busy. This is the key measurement for identifying bufferbloat.
5. Download & Upload Speed
You can also see your connection’s measured download and upload speeds alongside your latency results.
6. Detailed Ping Statistics
You can also review minimum, mean, median, maximum, and jitter values for each test phase. These numbers show your latency and how consistent your connection is.
7. Latency Visualization
The per-ping results make it easier to see how latency changes between an unloaded connection and connections under download or upload activity.
8. Real-World Activity Predictions
For nontechnical users, our tool shows how your connection is expected to perform for activities such as web browsing, audio calls, 4K streaming, video conferencing, and latency-sensitive tasks.
9. Browser-Based Testing
Run the test without installing specialized networking software or using command-line tools.
10. Free With No Signup
You can use this tool for free without any signup or login.
How To Interpret Bufferbloat Test Results
The test gives you several results, but they all answer one main question: Does your connection stay responsive when it's busy?
Here’s the breakdown of the results and what they mean.
1. Bufferbloat Grade (A to F)
This is your overall result. It is based on how much your latency increases when your connection is under load.
- A: Very little increase in latency
- B: Small increase
- C or lower: Larger latency increase
An A or B is a good result. A lower grade means your latency increases more when your connection is under load. This can be a sign of bufferbloat.
2. Latency: Unloaded vs. Active
This is one of the most important parts of the test.
- Unloaded latency: Your ping when your connection is idle.
- Active latency: Your ping while downloading or uploading.
A small difference between the two is good. If your ping jumps from 30 ms to 300 ms when downloading, for example, your connection is becoming much less responsive under load. This is essentially what the grade shows as well.
3. Download and Upload Speed
These show your measured internet speeds. They are useful for context, but they don't determine whether you have bufferbloat. Even a very fast connection can have high latency under load. For a detailed speed test, use our dedicated internet speed test tool.
4. Your Connection
This section shows how higher latency may affect gaming, video calls, streaming, and web browsing. It compares your connection when it is idle with how it performs under load.
5. Jitter and Latency Range
Jitter shows how much your ping changes from one measurement to another. Lower jitter means a more consistent connection.
A large difference between the minimum and maximum latency can indicate that your connection becomes unstable when it's under load.
Putting It All Together
A good result usually means you have a high grade, a small increase in latency, low jitter, and mostly positive activity ratings.
If your latency increases sharply and you receive a low grade, your connection may have bufferbloat. In many cases, router features such as Smart Queue Management (SQM) or QoS can help reduce it.
FAQs
What is bufferbloat?
Bufferbloat happens when your connection gets busy, and your latency suddenly shoots up. You might notice this as lag in games, delays during video calls, or websites taking longer to respond while someone downloads or uploads.
What is a good bufferbloat grade?
An A or B is generally a good result. It means your latency doesn't increase much when your connection is under load. If you get a lower grade, your connection may be struggling to stay responsive when it's busy.
Why is my ping higher during a download?
That's usually because the download is using most of your available bandwidth, causing packets to wait in network buffers. If your ping jumps a lot while downloading, that's a common sign of bufferbloat.
Can I have bufferbloat with fast internet?
Yes. A fast connection can still have bufferbloat. Your download and upload speed tell you how much data your connection can move, while the bufferbloat test looks at whether your connection stays responsive while doing that.
How can I reduce bufferbloat?
You can often reduce bufferbloat through your router's traffic-management settings. Smart Queue Management (SQM) and properly configured QoS can help manage network queues and reduce latency under load.