Idle latency
Your baseline response time when the connection is relatively quiet.
Connection responsiveness
Fast broadband should still feel fast when it is busy
A normal speed test measures capacity. A loaded latency test asks a different question: what happens to ping when the line is carrying a large download or upload?
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 latency is low | The line is fine when quiet | Check download-loaded and upload-loaded latency next. |
| Upload loaded latency is high | Backups, CCTV or file uploads filling upstream | Pause uploads or configure SQM/QoS. |
| Both loaded results are high | Router queues, Wi‑Fi or provider congestion | Compare Ethernet and Wi‑Fi, then test at another time. |
Free browser test
Measure idle, download and upload latency automatically
The LinkSpeed bufferbloat test measures a quiet baseline, creates download and upload traffic, and continues checking latency while the connection is busy. It then reports the worst added delay.
What loaded latency measures
Latency—often called ping—is the time taken for a small request to travel to a server and return. It is measured in milliseconds. Throughput and latency describe different parts of broadband performance: a connection can move a great deal of data each second but still respond slowly when its queues fill.
Download-loaded latency
Ping measured while incoming traffic is filling the available download capacity.
Upload-loaded latency
Ping measured while outgoing traffic is filling the usually smaller upload capacity.
Added latency
The loaded result minus the idle result. This is the most useful comparison.
Example: 18 ms idle latency and 93 ms upload-loaded latency means the upload created 75 ms of added latency.
How to grade a loaded latency result
Use the largest increase above idle latency from the download and upload phases. Lower is better.
| Added latency | LinkSpeed rating | Likely experience under load |
|---|---|---|
| 0–5 ms | A+ Exceptional | Responsiveness changes very little. |
| 6–15 ms | A Excellent | Well controlled for gaming, calls and mixed use. |
| 16–30 ms | B Good | Usually comfortable, with occasional small delays. |
| 31–60 ms | C Fair | Lag may become noticeable while the line is busy. |
| 61–120 ms | D Poor | Games, calls and interactive apps may struggle. |
| Over 120 ms | F Severe | Heavy traffic is likely to cause obvious delay. |
These are LinkSpeed guidance bands, not an industry certification. Browser load, Wi-Fi, VPNs, other users, routing and the test server can affect results. Repeat the test before changing equipment.
Why high loaded latency causes real problems
Online gaming
Inputs and voice chat can lag when another device downloads a game or uploads video.
Video calls
Queued packets can cause delayed speech, frozen video and people talking over one another.
Remote work
Cloud sync can make remote desktops and web applications feel slow despite high download speed.
Mobile broadband
Changing capacity and signal conditions can produce unstable loaded latency on 4G or 5G services.
Why does loaded latency increase?
When a connection reaches capacity, routers, modems and network equipment hold packets in a queue. Some queuing is normal. The problem appears when the queue becomes unnecessarily long and small, time-sensitive packets must wait behind bulk traffic.
How to get a reliable test result
- Use Ethernet first.This separates router or line queuing from weak or congested Wi-Fi.
- Pause unrelated traffic.Begin with a controlled test so the tool itself creates the measured load.
- Disable a VPN temporarily.Only for diagnosis; a VPN changes the route and can add variable delay.
- Keep the tab active.Browser power-saving and background-tab limits can affect timing.
- Repeat the test.Compare two or three runs, including a busy evening if problems are time-dependent.
- Retest on Wi-Fi.If Ethernet is good but Wi-Fi is poor, focus on wireless coverage and interference.
How to reduce loaded latency
- Enable effective Quality of Service or Smart Queue Management if the router provides it.
- Look for SQM, CAKE or FQ-CoDel support rather than relying only on simple device priority.
- Set traffic shaping slightly below stable real-world download and upload speeds so the router controls the bottleneck.
- Limit cloud backup, large uploads, security-camera traffic and game downloads during calls or gaming.
- Use Ethernet for latency-sensitive devices and improve router or mesh placement for Wi-Fi users.
- Update router firmware and consider newer equipment if the current router lacks useful queue management.
Loaded latency FAQs
Is loaded latency the same as normal ping?
Normal or idle ping is measured when the connection is quiet. Loaded latency measures ping while download or upload traffic is competing for capacity.
Why is upload loaded latency often worse?
Many broadband packages have substantially less upload capacity than download capacity. A backup or large file upload can therefore fill the upstream queue much more easily.
Will faster broadband fix loaded latency?
Extra capacity can make saturation less frequent, but speed alone does not guarantee good queue management. A correctly configured router may make a larger difference under full load.
Can full fibre still have bufferbloat?
Yes. Full fibre can provide excellent capacity and low idle latency, but queues can still build when the connection is saturated or the router handles traffic poorly.
Should I test on Wi-Fi?
Test Ethernet first for the clearest line/router result, then repeat on Wi-Fi to understand the experience at the device.