Washington / Seattle / Quantum Fiber vs Xfinity

Quantum Fiber vs Xfinity in Seattle

Seattle’s trade-off is Xfinity’s broader, cheaper cable service versus Quantum Fiber’s faster uploads where its fiber reaches your address.

The 30-Second VerdictUpdated September 21, 2026

Xfinity is the better overall pick in Seattle because it reaches more homes, starts at a lower price, and offers stronger download performance where available. Xfinity wins on coverage and price, while Quantum Fiber wins on upload speed; both have a 90/100 speed score. Quantum Fiber is right for households that upload large files, work from home, or want more balanced performance, while Xfinity suits shoppers prioritizing availability and a lower starting rate. Check your address before choosing, since plan availability varies block to block.

By Austin Shrum and Ali Yazdi, co-founders. Both spent years selling internet plans online before building this site. Every figure above comes from FCC Broadband Data Collection filings and monthly price checks; here is how we rank providers.

At a glance

Quantum Fiber vs. Xfinity, side by side.

Provider	Type	Top speed	City coverage	Starting price	Best for
Quantum Fiber	Fiber	2 Gig 1 Gig upload	76%	$50/mo	Top fiber speeds
Xfinity	Cable	2 Gig 300 Mbps upload	98%	$40/mo	Widest availability

Coverage map

Two different questions, two views. Top speed shows who offers the faster plan where you can actually get it. Coverage shows who reaches more of each ZIP. Or pick a single provider to see just its footprint.

View

Showing the provider with the faster available plan in each ZIP. Click any ZIP for the breakdown.

Neighborhood breakdown

Xfinity reaches about 98% of Seattle overall, while Quantum Fiber reaches about 76%, but availability can change from one block to the next. Quantum Fiber’s 2,000/1,000 Mbps plan reaches about 70% of the city, so verify the exact address before prioritizing fiber uploads.

ZIP	Neighborhoods	Coverage		Top speed		Rank score		Winner
ZIP	Neighborhoods	Quantum Fiber	Xfinity	Quantum Fiber	Xfinity	Quantum Fiber	Xfinity	Winner
98103	Fremont, Wallingford, Greenwood, Green Lake	91%	100%	8 Gig	2 Gig	82	79	Quantum Fiber
98115	Wedgwood, View Ridge, Bryant, Maple Leaf	81%	100%	8 Gig	2 Gig	73	79	Xfinity
98144	Beacon Hill, Mount Baker, Leschi, Judkins Park	74%	92%	8 Gig	2 Gig	67	73	Xfinity
98108	Georgetown, Beacon Hill, South Park	67%	80%	8 Gig	2 Gig	60	64	Xfinity
98118	Columbia City, Rainier Valley, Seward Park, Hillman City	88%	99%	8 Gig	2 Gig	79	79	Xfinity
98117	Ballard, Crown Hill, Loyal Heights, Sunset Hill	94%	100%	8 Gig	2 Gig	85	79	Quantum Fiber
98133	Bitter Lake, Broadview, Haller Lake, North Seattle	67%	100%	8 Gig	2 Gig	60	79	Xfinity
98122	Central District, First Hill, Madrona, Leschi	54%	99%	8 Gig	2 Gig	49	79	Xfinity
98126	West Seattle, Delridge, North Delridge, Genesee	91%	98%	8 Gig	2 Gig	82	78	Quantum Fiber
98168	Tukwila, Riverton, Boulevard Park, White Center	67%	98%	2 Gig	2 Gig	60	78	Xfinity
98125	Northgate, Lake City, Maple Leaf, Pinehurst	88%	100%	8 Gig	2 Gig	79	79	Xfinity
98105	University District, Ravenna, Laurelhurst, Roosevelt	62%	100%	8 Gig	2 Gig	56	79	Xfinity
98178	Rainier Beach, Bryn Mawr, Skyway, Lakeridge	74%	98%	8 Gig	2 Gig	67	78	Xfinity
98198	Des Moines, Redondo, Woodmont	17%	99%	8 Gig	2 Gig	15	79	Xfinity
98112	Madison Park, Montlake, Madison Valley, Capitol Hill	75%	100%	8 Gig	2 Gig	67	79	Xfinity
98155	Lake Forest Park, Shoreline, Kenmore	82%	100%	8 Gig	2 Gig	74	79	Xfinity
98109	South Lake Union, Queen Anne, Westlake	52%	99%	8 Gig	2 Gig	47	79	Xfinity
98177	Broadview, Blue Ridge, North Beach, Carkeek Park	47%	100%	8 Gig	2 Gig	43	79	Xfinity
98107	Ballard, Adams, Loyal Heights	79%	100%	8 Gig	2 Gig	71	79	Xfinity
98119	Queen Anne, Interbay, Uptown	67%	98%	8 Gig	2 Gig	60	78	Xfinity
98116	West Seattle, Alki, Admiral, Fauntleroy	94%	100%	8 Gig	2 Gig	85	79	Quantum Fiber
98146	White Center, Highland Park, West Seattle, Arbor Heights	90%	100%	2 Gig	2 Gig	81	79	Quantum Fiber
98136	West Seattle, Fauntleroy, Fairmount Park, The Junction	94%	100%	8 Gig	2 Gig	84	79	Quantum Fiber
98102	Capitol Hill, Eastlake, Montlake	62%	100%	8 Gig	2 Gig	56	79	Xfinity
98104	Pioneer Square, Chinatown-International District, First Hill	16%	82%	8 Gig	2 Gig	14	65	Xfinity
98106	Highland Park, South Delridge, Riverview	90%	99%	8 Gig	2 Gig	81	78	Quantum Fiber
98188	Tukwila, Riverton Heights, McMicken Heights	36%	95%	8 Gig	2 Gig	33	76	Xfinity
98199	Magnolia, Lawton Park, Interbay, Discovery Park	72%	99%	8 Gig	2 Gig	65	79	Xfinity
98134	SoDo, Industrial District, Georgetown	30%	76%	8 Gig	2 Gig	27	60	Xfinity
98148	Burien, Normandy Park, SeaTac	46%	99%	8 Gig	2 Gig	41	79	Xfinity
98166	Burien, Normandy Park, Three Tree Point	61%	100%	2 Gig	2 Gig	55	79	Xfinity
98101	Downtown, Retail Core, Denny Triangle	11%	95%	8 Gig	2 Gig	10	76	Xfinity
98194	Downtown Seattle, Pioneer Square, Waterfront	25%	69%	8 Gig	2 Gig	22	55	Xfinity
98124	Downtown Seattle, Central Business District	30%	76%	8 Gig	2 Gig	27	60	Xfinity
98139	Interbay, Magnolia	49%	100%	2 Gig	2 Gig	44	79	Xfinity
98121	Belltown, Denny Regrade, Waterfront	17%	97%	8 Gig	2 Gig	15	77	Xfinity
98138	Tukwila	13%	94%	2 Gig	2 Gig	12	75	Xfinity
98113	Northgate, Ballard	100%	100%	2 Gig	2 Gig	90	79	Quantum Fiber
98164	Downtown Seattle, Pioneer Square	18%	93%	8 Gig	2 Gig	16	74	Xfinity
98111	Downtown Seattle, Central Business District	18%	93%	8 Gig	2 Gig	16	74	Xfinity

Rank score (0–100) is each provider’s Speed Score, discounted for weak upload, times the share of that ZIP it reaches — the same rule that orders providers on the Seattle city page, so it moves as availability changes street to street.

Which is better for…

The right pick comes down to what you actually do online.

Gaming

Quantum Fiber

Quantum Fiber’s 2,000/1,000 Mbps plan reaches about 70% of the city where available, giving gamers substantially more upload capacity for live play and sharing. Check that the fiber tier reaches your address.

Streaming

Xfinity

Xfinity’s 2,000/300 Mbps plan reaches about 82% of the city where available, which is ample download capacity for multiple high-quality streams. Its lower $40/mo starting price also makes it the easier value choice.

Video calls

Quantum Fiber

Quantum Fiber’s 2,000/1,000 Mbps tier reaches about 70% of the city, while Xfinity’s 2,000/300 Mbps tier reaches about 82%. Quantum’s 1,000 Mbps upload is better suited to frequent calls, large uploads, and busy home networks.

Just the basics

Xfinity

Xfinity starts at $40/mo, compared with Quantum Fiber at $50/mo, and reaches about 98% of Seattle overall. For browsing, email, and occasional streaming, the cheaper, more widely available option is enough.

Get connected

Pick your provider and check availability at your address.

Check plans

Top speed2 Gig

Upload1 Gig

Coverage76%

From$50/mo

2 Gig down · 1 Gig up Fiber
1 Gig down · 1 Gig up Fiber

Check plans

Top speed2 Gig

Upload300 Mbps

Coverage98%

From$40/mo

2 Gig down · 300 Mbps up Cable
1 Gig down · 35 Mbps up Cable

See what’s actually available at your address

Coverage changes from one street to the next. Check your exact address in seconds.

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Frequently asked questions

Is Quantum Fiber or Xfinity available at my Seattle address?

Xfinity reaches about 98% of Seattle overall, while Quantum Fiber reaches about 76%. Coverage varies block to block, so enter your exact address to confirm which provider and tier are available.

Which is cheaper, Quantum Fiber or Xfinity, and what will I actually pay?

Xfinity starts at $40/mo, while Quantum Fiber starts at $50/mo. These are promotional starting rates, so confirm the post-promo rate, equipment fees, and any contract before signing; check the full offer for your address.

Which is faster for gaming, work from home, or 4K streaming?

Both providers have a 90/100 speed score. Quantum Fiber’s 2,000/1,000 Mbps plan reaches about 70% of the city, while Xfinity’s 2,000/300 Mbps plan reaches about 82%; choose Quantum Fiber where available if upload performance matters, and verify the tier at your address.

How we compare. Coverage is the share of a ZIP where a provider offers a genuinely good plan (≥ 1 Gbps download, ≥ 20 Mbps upload, non-satellite), from FCC Broadband Map serviceability data. “Fastest available” ranks the providers present in a ZIP by top advertised download speed. Pricing reflects current promotional starting rates. Provider order and each ZIP’s winner follow the site’s one ranking rule (Speed Score, discounted for weak upload, times coverage); read the full methodology.