Quantum Fiber Speed Test - Check Your Fiber Speed
Test your Quantum Fiber internet speed in United States
www.quantumfiber.comQuantum Fiber is a fiber-optic internet service originally launched by Lumen Technologies as the fiber brand successor to CenturyLink. Quantum Fiber serves nearly 1 million subscribers across 11 states with speeds from 500 Mbps to 8 Gbps. AT&T completed its acquisition of Quantum Fiber in early 2026. Test your Quantum Fiber connection to measure actual download, upload, and latency performance.
About Quantum Fiber
Quantum Fiber launched in 2020 as Lumen Technologies' dedicated fiber internet brand, separating fiber service from the legacy CenturyLink DSL brand. Headquartered in Monroe, Louisiana, Quantum Fiber built a network covering over 4 million locations across 11 states.
In May 2025, Lumen announced the sale of 95% of Quantum Fiber to AT&T for $5.75 billion, with the transaction closing in early 2026. AT&T plans to migrate Quantum Fiber subscribers to its AT&T Fiber network. Quantum Fiber's Price for Life guarantee locks in the monthly rate for as long as the customer maintains service.
Quantum Fiber Plans and Services
Quantum Fiber offers several internet plans across different technologies and price points.
Quantum Fiber plans range from $50 to $165 per month with speeds from 500 Mbps to 8 Gbps. The 500 Mbps plan starts at $50 and 1 Gbps at $75, both with symmetrical upload speeds. Multi-gig options include 4 Gbps at $120 and 8 Gbps at $165 per month.
All plans include the Price for Life guarantee with no price increases. No data caps, no contracts, and free professional installation. WiFi equipment is included with all plans.
Quantum Fiber Internet Plans
| Plan | Speed | Price | Features |
|---|---|---|---|
| Quantum Fiber 500 fiber | 500 Mbps | $50/month |
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| Quantum Fiber 1 Gig fiber | 1000 Mbps | $75/month |
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| Quantum Fiber 4 Gig fiber | 4000 Mbps | $120/month |
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| Quantum Fiber 8 Gig fiber | 8000 Mbps | $165/month |
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Prices and availability may vary by location. Contact Quantum Fiber for current offers.
Test Your Quantum Fiber Speed
Run a free speed test to check if Quantum Fiber delivers the speeds you are paying for. Test during peak evening hours for the most realistic results. Compare your results against Quantum Fiber advertised speeds above.
Quantum Fiber Speed Test FAQ
How fast is Quantum Fiber?
Quantum Fiber offers symmetrical fiber speeds from 500 Mbps to 8 Gbps depending on plan and location. Most areas have access to 500 Mbps and 1 Gbps plans. Multi-gig speeds of 4 Gbps and 8 Gbps are available in select markets using XGS-PON technology. All speeds are symmetrical, meaning upload speeds match download speeds. Actual performance depends on your plan tier and home network equipment.
What is Price for Life?
Quantum Fiber's Price for Life guarantee means your monthly internet rate will not increase for as long as you maintain your Quantum Fiber service. This applies to the base internet price and protects customers from annual price hikes common with other ISPs. The guarantee remains in effect through any plan continuation. If you voluntarily downgrade or suspend service, rates may revert to current standard pricing.
Is Quantum Fiber the same as CenturyLink?
Quantum Fiber is the fiber-optic internet brand created by Lumen Technologies to replace CenturyLink for fiber customers. CenturyLink continues to serve DSL customers while Quantum Fiber handles all fiber connections. Both brands were owned by Lumen Technologies. In 2025, AT&T announced the acquisition of Quantum Fiber, which means subscribers will eventually transition to AT&T Fiber service.
How do I test my Quantum Fiber speed?
Use the speed test tool on this page to measure your Quantum Fiber download speed, upload speed, and ping latency. For accurate fiber results, connect your device directly to the router using an ethernet cable. Ensure no other devices are heavily using the network during the test. Quantum Fiber should deliver consistent speeds close to your plan tier since fiber is not affected by distance or shared neighborhood bandwidth.