Test your CenturyLink 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 CenturyLink speed test to measure your CenturyLink DSL or Quantum Fiber connection. The test shows download speed, upload speed, ping, and jitter in under a minute.
CenturyLink DSL speeds vary widely by distance from the central office — from as low as 10 Mbps to around 100 Mbps. Quantum Fiber (CenturyLink’s fiber brand) offers 200 Mbps to 940+ Mbps with fast, symmetric uploads.
On CenturyLink DSL, your speed is limited by the copper line distance to the nearest central office. Results far below your plan speed on DSL often mean line issues — not Wi-Fi problems.
Quantum Fiber delivers consistent, symmetric speeds. On a wired connection you should see results very close to your plan rate in both directions.
DSL slowdowns are commonly caused by line noise, old in-home wiring, or DSL filters missing on phone jacks. Make sure every phone device shares the line through a filter.
Test with a computer wired directly to the modem, bypassing the router. If speeds are still low, CenturyLink support can run a line test and check your signal levels.
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.
On Quantum Fiber, expect close to your plan speed with matching uploads. On DSL, anything close to your plan’s rated speed is good — DSL rarely exceeds its provisioned rate.