Connection Stability Test
A speed number cannot tell you whether your connection keeps dropping out. This test sends a tiny request every quarter of a second and draws the result, so you can see lag spikes and lost requests as they happen.
Black line: delay of each request in milliseconds. Red marks: requests that got no answer within 2 seconds.
What the test measures
The test sends a very small request to our server about four times a second and records how long each one takes to come back. It then reports:
- Lost requests: requests that got no answer within two seconds.
- Typical delay: the median time of the answered requests.
- Delay spikes: answers that took far longer than usual.
- Drops: runs of several lost requests in a row, which is what you feel as a freeze.
- Jitter: how much the delay changes from one request to the next.
How to read the result
Stable means every request was answered and the delay stayed steady. Mostly stable allows a few slow or lost requests. Unstable means requests are lost or delayed regularly, which shows up as frozen calls and lag spikes in games. If you see regular drops at similar intervals, something on your network may be restarting or interfering.
Common causes of an unstable connection
- Weak or crowded Wi-Fi. Test again next to the router, or on a cable. See Wi-Fi vs Ethernet.
- A busy line. Large uploads and downloads can cause delay spikes. Check with the bufferbloat test.
- A faulty cable, modem or router. Loose or damaged cables and overheating equipment cause drops.
- Interference or a line fault. If drops continue on a cable, contact your provider and share the graph.
For the background on delay and variation, read what ping and jitter mean.
About this tool
The test uses the same tiny request as the CHECKiOX ping test, so it uses very little data: well under 1 megabyte for a full run. It measures the path between your device and our server, which is a good guide to your own connection but not to every website.
Frequently asked questions
How do I test if my internet connection is stable?
Run the stability test above for at least 60 seconds. It reports lost requests, delay spikes and drops. A stable connection loses nothing and keeps a steady delay.
Why does my internet keep dropping?
Common causes are weak Wi-Fi, a faulty cable or router, interference, or a fault on your provider's line. Test on an Ethernet cable to tell Wi-Fi problems from line problems.
What is a good result on a stability test?
No lost requests, a steady delay with few spikes, and no drops. A loss of a couple of percent or less is usually still fine for browsing but may cause occasional glitches in calls and games.
What causes lag spikes?
Lag spikes come from a busy line, weak Wi-Fi, other devices using bandwidth, or equipment problems. The bufferbloat test can show whether load on your line causes them.
Does the stability test use much data?
No. The requests are tiny: even a two-minute run uses well under 1 megabyte.
Related tools and guides
- Bufferbloat and packet loss test: delay when the line is busy.
- What is ping and jitter?: the numbers explained.
- Wi-Fi vs Ethernet: which is steadier.
- How to improve your internet speed: a full checklist.