Test over Ethernet
If Ethernet is stable but Wi‑Fi is not, fix the home network before changing provider.
Internet quality test
Bufferbloat fibre test and loaded latency checker
Fast broadband can still lag if ping rises when the line is busy. Run a LinkSpeed speed test, repeat it while downloads or uploads are active, then enter the ping values below to grade your bufferbloat.
Troubleshooting route
Broadband troubleshooting hub → start with the issue, validate the cause, then follow the matching fix steps.
Issue → Validate → Fix
Use the symptom to choose the right test
| Issue | Validate | Fix |
|---|---|---|
| Idle ping is good | Connection is responsive when quiet | Now compare ping while download/upload load is active. |
| Ping rises during upload | Upload queueing or bufferbloat | Enable SQM/QoS or limit upload-heavy devices. |
| Ping rises during download | Download queueing or overloaded router | Use Ethernet, update router, and shape bandwidth if available. |
Quick answer
How do I know if I have bufferbloat?
You probably have bufferbloat if your idle ping is low but your ping jumps sharply during downloads, uploads, cloud backups, game updates or multiple streams.
For gaming and video calls, the important number is the increase in latency under load. A small rise is normal. A large rise means the connection is queuing traffic instead of keeping it responsive.
Bufferbloat test
Enter your idle and loaded ping results
Run one speed test when the connection is quiet. Then start a large download or upload and run the test again. Enter the ping values below to grade the added latency.
Ready
Enter results to grade bufferbloat
Compare idle ping with loaded download and upload ping.
How to grade the result
Use the largest increase between idle ping and loaded ping. For example, if idle ping is 12 ms and loaded upload ping is 110 ms, the added latency is 98 ms.
| Added latency under load | Grade | What it feels like |
|---|---|---|
| 0–25 ms | Excellent | Gaming and calls should stay responsive while the line is busy. |
| 25–60 ms | Good / mild | Usually usable, but fast games may feel slightly less sharp. |
| 60–150 ms | Likely bufferbloat | Noticeable lag during downloads, uploads, video calls or streaming. |
| 150 ms+ | Severe | Games, calls and remote work may stutter badly when the connection is busy. |
Why does gigabit or full fibre broadband still lag?
Gigabit broadband removes many speed bottlenecks, but it does not remove every latency problem. Wi‑Fi interference, overloaded routers, upload saturation, old hardware and poor queue management can still cause ping spikes.
Idle ping
12 ms Download or upload starts Queue builds Loaded ping
140 ms Gaming lag
12 ms Download or upload starts Queue builds Loaded ping
140 ms Gaming lag
What to fix first
Enable SQM or QoS
Smart Queue Management, CAKE or FQ-CoDel can keep latency lower when the line is busy.
Control uploads
Cloud backups, cameras, livestreams and file uploads often create the biggest latency spikes.
Retest after changes
Repeat the same idle and loaded test so you know whether the fix actually worked.
FAQs
What is a bufferbloat test?
A bufferbloat test compares idle ping with ping while downloads or uploads are active. A large increase suggests queues are building up and causing lag.
Can full fibre have bufferbloat?
Yes. Full fibre and gigabit broadband can still suffer from bufferbloat if your router or network queues become overloaded.
Is upload or download bufferbloat worse?
Upload bufferbloat is often worse because many broadband packages have much lower upload capacity. Cloud backups, video uploads and security cameras can fill the upload queue quickly.
Does QoS fix bufferbloat?
Some QoS helps, but modern SQM using approaches such as CAKE or FQ-CoDel is usually better than simple device priority. Results depend on router support and setup.