Internet Health Test
This internet health test measures your connection live from this browser: latency, jitter, how much latency rises when the line is busy, failed requests, and download and upload speed, then checks each against a published standard. It cannot count lost packets or test the route to every website; it measures to the nearest Cloudflare data centre.
Takes about 30 seconds and uses up to 36 MB of data (less on a slow line). Pause downloads and streaming on other devices for a fair result.
Ready.
Latency (idle)
—ms
Jitter
—ms
Latency (busy)
—ms
Download
—Mbps
Upload
—Mbps
Failed requests
—
Result
What this connection can handle
One test is one moment. Results change with the time of day, Wi-Fi signal and what else is using the line, so run it two or three times before you call your provider. Speed is measured over one connection, so very fast lines (several hundred Mbps and up) may read lower than their real capacity.
What the Internet Health Test Checks
An internet health test checks whether your connection is stable, not only whether it is fast. A line can show a big download number and still drop video calls, because calls and games depend on steady, low delay. This test measures six things from your browser and grades the ones that decide how the internet feels to use.
- Latency (idle): the round trip from your device to the test server and back, timed over 15 small requests while nothing else is running.
- Jitter: how much the latency changes from one request to the next. This test reports the average change between consecutive requests.
- Latency (busy): the same round trip measured while the test is downloading and uploading. A big rise here is called bufferbloat.
- Download and upload speed: timed transfers that grow in size until one takes about two seconds.
- Failed requests: test requests that got no answer within the time limit.
All requests go to Cloudflare's public speed test service (speed.cloudflare.com), which answers from the data centre nearest to you. The page shows the code of the data centre that answered, such as LHR for London. Nothing is sent to Teamz Lab, and there is no account or app to install.
How to Read Your Results
Each check is graded against a published figure, so a pass or fail means something outside this page. The table lists the rule and where it comes from.
| Check | Passes when | Source |
|---|---|---|
| Latency | 95% of idle requests take 100 ms or less | FCC and NTIA low-latency rule for subsidised broadband (RDOF and BEAD programmes) |
| Latency (busy) | Median stays at 100 ms or less under load | Same FCC and NTIA 100 ms rule |
| Jitter | 30 ms or less | Cisco QoS design guidance for voice |
| HD video | Download 5 Mbps or more | Netflix Help Center |
| 4K video | Download 15 Mbps or more | Netflix Help Center |
| Voice and video calls | Jitter 30 ms or less and latency 300 ms or less | Cisco; ITU-T G.114 (150 ms one way, so about 300 ms there and back) |
| Broadband benchmark | 100 Mbps down and 20 Mbps up | FCC fixed broadband benchmark, set in March 2024 |
The overall result is Healthy when every request was answered, latency and jitter pass, latency stays low while busy, and download speed is enough for HD video. Falling short of the FCC 100/20 benchmark is shown, but on its own it does not mark a line as unhealthy: plenty of homes work well on less.
Why Latency Under Load Matters
Most routers and modems hold a queue of data waiting to be sent. When someone starts a big download or a cloud backup, that queue fills, and every other packet has to wait behind it. Your speed test still looks fine, but a video call in the next room starts to stutter and a game starts to lag. That is bufferbloat, and it is the most common reason a "fast" connection feels bad.
This test catches it by timing small requests while its own download and upload are running. If idle latency is low but busy latency jumps, the queue in your router or modem is the likely cause. Many routers have a setting called SQM, Smart Queue Management or QoS that keeps the queue short; turning it on and setting it a little below your measured speed usually fixes it.
What This Test Cannot Tell You
A web page can only make normal web requests, so some things are out of reach:
- Packet loss. Web requests run over TCP, which resends lost packets silently. A browser cannot count them without a server built for it, so this page reports failed requests instead and never prints a "packet loss %".
- Every route. The test measures the path to one Cloudflare data centre. A problem between your provider and one particular game server or website will not show here.
- Wi-Fi versus provider. The result covers everything between this device and the server. To tell a Wi-Fi problem from a provider problem, run the test again on a cable, or standing next to the router, and compare.
For a closer look at raw speed, try the internet speed test, or browse more free online tools.
How to Fix an Unhealthy Connection
- Restart the modem and router, wait two minutes, and test again.
- Test on a cable or right next to the router. If the result improves a lot, the problem is Wi-Fi: move the router higher and away from walls, or add a mesh point.
- Pause cloud backups, game updates and streaming on other devices, then test again.
- If latency rises sharply while busy, turn on SQM or Smart Queue in the router settings.
- Turn off a VPN for one run. A VPN adds distance and can add latency.
- If failed requests or high latency remain on a cable, copy your result and send it to your provider, with the time of day you tested.
Frequently Asked Questions
What is an internet health test?
It is a check of how well your connection works, not only how fast it is. This one measures latency, jitter, latency while the line is busy, failed requests and download and upload speed from your browser, then grades each against a published standard such as the FCC 100 ms low-latency rule.
Is my internet healthy if the speed is high?
Not always. A fast line can still have high jitter or large latency spikes when busy, which makes calls stutter and games lag. That is why this test grades latency, jitter and latency under load, and only calls a line healthy when those pass too.
Does this test show packet loss?
No. Browsers send web requests over TCP, which resends lost packets automatically, so a web page cannot count them. The test reports failed requests instead: requests that got no answer in time. Any failed request is worth a second run on a cable.
How much data does the test use?
Up to about 25 MB for download and 10 MB for upload, plus a few kilobytes for latency checks. On a slow line it stops early and uses much less. If you are on a capped mobile plan, run it on Wi-Fi.
Why are my results different from other speed tests?
Each test uses different servers, a different number of connections and a different method. This one measures to the nearest Cloudflare data centre over one connection, so very fast lines may read lower than a multi-connection test. Compare runs of the same test over time rather than across tests.
Is the test private?
The test requests go straight from your browser to Cloudflare's public speed test service. Teamz Lab does not receive or store your results, and you do not need an account.