How Speedtest.now Works

The Short Version

Speedtest.now runs a browser-based network test against a nearby server. It measures download speed, upload speed, ping, jitter, and packet loss, then shows the result in plain language so you can tell whether your connection is fast, stable, or both.

Step 1 - Choosing a Test Server

The test uses an available Speedtest.now server and measures round-trip delay before the main throughput phases begin. A closer server usually gives a cleaner view of your access connection, while a distant server can add routing delay that is not caused by your home internet plan.

Step 2 - Measuring Ping and Jitter

Before testing speed, we send multiple lightweight requests and calculate latency. Ping is the round-trip delay. Jitter is how much that delay varies from sample to sample. A connection can have high download speed but still feel bad if jitter is high.

Step 3 - Measuring Download Speed

The download phase pulls test data over multiple parallel HTTP streams. Parallel streams help saturate modern broadband connections and avoid under-reporting fast fibre or cable plans. We report the measured throughput in Mbps.

Step 4 - Measuring Upload Speed

The upload phase sends data from your browser to the server. Upload matters for video calls, cloud backups, live streaming, remote work, and sending large files. Many cable and DSL plans have much lower upload than download, so this result often explains real-world frustrations.

Step 5 - Checking Packet Loss

Packet loss means some requests never complete successfully. Even tiny packet loss can cause broken calls, game lag, and TCP slowdowns. That is why Speedtest.now reports packet loss separately instead of hiding it inside the speed number.

How Results Become Rankings

Eligible results contribute to rolling country and ISP rankings after quality checks. Rankings use medians rather than one-off peaks, so a single unusually fast or slow result does not dominate the data. Read the full measurement methodology for the technical detail.

How to Get the Most Accurate Result

Use Ethernet if possible, pause downloads and cloud backups, close streaming apps, and test more than once. If your speed changes dramatically by time of day, compare morning and evening results to identify congestion. Our accuracy guide walks through the checklist.