Test your Xfinity (Comcast) connection speed below
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This test measures the connection to your current device, not the speed delivered directly to your gateway or modem.
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Use this free Xfinity speed test to measure your Comcast Xfinity internet connection in under a minute. The test checks your download speed, upload speed, ping (latency), and jitter using Measurement Lab’s global server network, and automatically finds the server closest to you.
Xfinity offers cable internet plans ranging from 150 Mbps up to 2,000 Mbps (2 Gbps) in most areas. Enter your plan speed below the test to see roughly what percentage of your advertised speed you are actually getting. If your result is consistently less than half of your plan speed, try the troubleshooting steps in the guides below before calling Xfinity support.
Xfinity’s most popular plans include 150 Mbps, 300 Mbps, 500 Mbps, 1,000 Mbps (Gigabit), and 2,000 Mbps (Gigabit x2) in select areas. Actual speeds are typically 10–20% below the advertised “up to” rate during normal use.
Xfinity upload speeds are much lower than download speeds on most cable plans — for example, a 300 Mbps plan usually includes around 10–20 Mbps upload. If you work from home or create content, Xfinity’s fiber-to-the-home plans (where available) offer faster, more symmetric uploads.
The most common causes of slow Xfinity speeds are an outdated modem or gateway, poor router placement, too many connected devices, and peak-hour congestion. Start by restarting your Xfinity gateway (unplug it for 60 seconds), then test again with a wired connection.
If wired speeds are fine but Wi-Fi is slow, the problem is your home network — try moving the gateway to a central, elevated spot, or consider Xfinity’s xFi pods for larger homes. If wired speeds are also low, check for area outages in the Xfinity app, then contact support.
For the most accurate result, connect your computer directly to your router with an Ethernet cable if possible. If you must use Wi-Fi, stand close to the router and disconnect other devices during the test.
Close streaming apps, cloud backups, and other browser tabs before clicking Start. Run the test 2–3 times at different times of day — speeds often dip during evening peak hours (7–11 PM) when many households are online.
Download speed (Mbps) controls how fast you can stream, browse, and download files. Upload speed (Mbps) affects video calls, live streaming, and cloud backups. Ping (ms) measures responsiveness — under 50 ms is good for gaming and calls. Jitter (ms) measures consistency — lower is better, especially for voice and video.
Compare your download result to your plan’s advertised speed. Most providers advertise “up to” speeds, so a result within about 20% of the advertised rate is normal.
Yes. Xfinity is the consumer brand name for Comcast’s residential internet, TV, and phone services. A Comcast speed test and an Xfinity speed test measure the same connection.