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Norynt

Internet testing

Why does my internet feel slow when it is busy?

Loaded Latency Test

Your calls and games fall apart whenever something else is downloading or backing up.

Is this happening to you?

  • A call freezes as soon as a big file starts sending.
  • Games lag while a console update runs in the background.
  • The internet feels fine until somebody else starts a download.

Loaded latency is your response time while the connection is working hard.

Start here

Does this sound familiar?

Three ordinary evenings that end up on this page.

  • Someone starts uploading holiday photos.

    Your work meeting begins to lag and freeze.

    This test helps explain why the two collide.

  • A console update starts downloading upstairs.

    Your game suddenly feels heavy and delayed.

    See what happens to your connection while it is busy.

  • Your phone backup runs in the background.

    Web pages crawl until the backup finishes.

    Let us measure that slowdown instead of guessing.

Can this help me?

Yes, if your connection is fine when it is quiet but falls apart when it is busy.

Why would I use this?
A fast connection can still feel slow when something is uploading.
When should I use this?
Use it when calls or games break up during a backup or a download.
What will I learn?
You learn how responsive your connection stays while it is busy.

What it will not tell you: It cannot prove which device or which piece of equipment created the delay.

Start here

Nothing happens until you press start.

How healthy is your internet?

Test your speed. Understand your connection. Know what to do next.

Your IP address is sent to Measurement Lab and published in their open dataset.

  • No account required
  • Takes about 20 seconds
  • Powered by Measurement Lab

What does this mean for me?

Here is how to read the numbers you get back.

  • The first number is how long your connection takes to answer while it is working hard.
  • The second is how much slower to answer it became compared with a quiet moment.
  • A small rise is normal. A large rise is why calls break up during a download.

Everyday use

Sizes and speeds are easier to judge with a familiar example.

  • A photo backup running in the background · 5 GB

    Holiday photos uploading can fill the line for several minutes.

  • A large PlayStation game downloading · 100 GB

    A big download keeps the line busy long enough to notice.

What should I do?

  1. Pause the download or backup, then run the test again.
  2. Look in your router settings for an option that protects calls and games.
  3. Change one thing at a time and test after each change.

What happens if I ignore this?

If you do nothing, large transfers keep interrupting games and video calls.

Check if this is the problem

Run a self-check when you want to test one change at a time.

Check this yourself

Common questions

Why does my latency rise during a test?
Data can queue up in buffers along the path while the line is full.
Can I improve this myself?
Some routers offer smart queue management, which often helps.

Learn more

These articles explain the idea behind this tool.

Technical details

The words behind the numbers, in case you want them. You do not need any of this to use the tool.

Loaded latency
The answer time measured while the connection is busy.
Bufferbloat
Delay that builds up when equipment lets too much data wait in line.
Smart Queue Management
A router setting that keeps that line short.

What you get back

  • Latency under load (ms) — Round trip while busy.
  • Increase over idle (ms) — How much it rose.

Norynt writes its own explanations. External documentation is listed only so you can verify what you read here.

Technical references

The information in this article is based on publicly available technical documentation and networking research. You do not need to read any of it to understand the article.

Measurement Lab(1)

The open measurement platform Norynt runs its speed tests on.

Bufferbloat research(1)

Research on delay caused by oversized network queues.