How to test your internet speed properly
Most speed tests are done wrong. Test wired vs WiFi, at the right time, with the right server — and learn what download, upload, ping and jitter each tell you.
A speed test is a measurement, and like any measurement it can be done in a way that tells you nothing. Three mistakes account for most useless results: testing over WiFi, testing at the wrong time, and reading only one of the four numbers.
Test in three places, not one
Do all three, in this order, and write the numbers down.
- Wired, at the router. Laptop with an Ethernet cable, WiFi switched off. This is your line's real capability.
- WiFi, next to the router. Same laptop, cable out, standing beside the router. This is your WiFi's ceiling.
- WiFi, where it hurts. The bedroom, the back room, the spot where video calls fail. This is what you actually experience.
If 1 is good and 3 is bad, your ISP is fine and the problem is coverage — go to router placement. If 1 is bad, the problem is upstream and no router will fix it.
Five rules for a trustworthy test
- Peak and off-peak. Run it at 7–8am and again at 9–10pm. The difference is the story.
- One device, nothing else running. A phone backup or a TV stream during the test invalidates it.
- Close the background apps. Cloud sync, Steam, OneDrive, iCloud Photos — all of them.
- Same server each time. Speedtest apps default to a nearby server; keep it consistent so you compare like with like.
- Repeat twice. A single run can land on a busy server. Take the second number, or the average of three.
What the four numbers mean
| Number | What it tells you | When it is the problem |
|---|---|---|
| Download | Capacity for streaming, downloads, browsing | Consistently under ~90% of plan speed when wired |
| Upload | Video calls, cloud backup, CCTV remote view, streaming out | Under 10 Mbps hurts 4K calls and remote work |
| Ping / latency | How long a round trip takes | Over 40 ms local feels sluggish; over 80 ms is bad for gaming |
| Jitter | How much ping varies | Over 20 ms causes calls to break up even at good speed |
| Packet loss | Data that never arrives | Anything above 0.5% is a fault worth reporting |
Download is the only number most people look at, and it is the least likely to explain "the internet feels slow". Browsing a page is dozens of small round trips: if ping is 200 ms, every page feels sluggish no matter how fast the pipe is.
The bufferbloat test nobody runs
When your line is saturated, a router with a deep buffer queues packets instead of dropping them, so latency can jump from 10 ms idle to 400 ms under load. Speed still looks fine. Games and calls become unplayable.
Run a test while something else downloads at full speed. If idle ping is 10 ms and loaded ping is 300 ms, you have bufferbloat. Fixes, in order of effectiveness: enable SQM/QoS on the router if it has it, cap the download slightly below line rate, or replace a router that has no queue management at all.
When to complain to your ISP
Bring evidence, not adjectives. A useful complaint contains:
- Plan name and account number
- Three wired tests: morning, evening, and one more evening on a different day
- The server used, and ping/jitter from the same tests
- Whether the wired and WiFi numbers differ
Providers will usually ask you to run their own app's test — do it, then attach your independent results next to theirs. Anything below roughly 90% of the advertised speed on a wired connection, repeatable across days, is worth escalating.
Two things to know before you argue:
- "Up to" speeds. Fibre in Malaysia is usually delivered close to the advertised rate, but consumer contracts are written around a percentage, not a guarantee.
- WiFi is not covered. No provider guarantees speed over WiFi. If your complaint is a WiFi number, the first answer will be "connect a cable", and that answer is technically correct.
If your line measures fine but the house feels slow, the honest conclusion is that you need coverage, not bandwidth: read mesh vs extender vs powerline and how much speed you actually need.