vs
Quantum Fiber vs Xfinity in Mercer Island
Mercer Island’s trade-off is broad, lower-starting-price Xfinity coverage versus Quantum Fiber’s fiber connection where its service reaches your address.
Xfinity is the better overall pick in Mercer Island because it reaches about 100% of the city and starts at $40/mo. Its 2,000/2,000 Mbps tier reaches about 100%, while Quantum Fiber’s 2,000/1,000 Mbps tier reaches about 48%. Xfinity wins on coverage and price; Quantum Fiber wins on upload performance where available, and both have a 90/100 speed score. Xfinity suits households wanting broad availability and a lower starting cost. Quantum Fiber fits upload-heavy work or creators who can get its service.
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 |
49% | $50/mo | Top fiber speeds |
| Xfinity |
Cable | 2 Gig 2 Gig upload |
100% | $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.
Neighborhood breakdown
Availability can shift block to block in Mercer Island. Xfinity reaches about 100% of the city overall, while Quantum Fiber reaches about 49%, so check your exact address before choosing; Quantum Fiber’s fastest 2,000/1,000 Mbps tier reaches about 48%.
| ZIP | Neighborhoods | Coverage | Top speed | Rank score | Winner | |||
|---|---|---|---|---|---|---|---|---|
| Quantum Fiber | Xfinity | Quantum Fiber | Xfinity | Quantum Fiber | Xfinity | |||
| 98040 | North End, East Seattle, First Hill, South End | 49% | 100% | 2 Gig | 2 Gig | 44 | 90 | 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 Mercer Island 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.
Get connected
Pick your provider and check availability at your address.
- 2 Gig down · 1 Gig up Fiber
- 1 Gig down · 1 Gig up Fiber
- 940 Mbps down · 940 Mbps up Fiber
See what’s actually available at your address
Coverage changes from one street to the next. Check your exact address in seconds.
Check my addressFrequently asked questions
Is Quantum Fiber or Xfinity available at my Mercer Island address?
Xfinity reaches about 100% of Mercer Island, while Quantum Fiber reaches about 49% overall. Availability can still vary block to block, so check both providers with your exact address before signing up.
Which is cheaper, Quantum Fiber or Xfinity, and what will I actually pay?
Xfinity starts at $40/mo, compared with Quantum Fiber at $50/mo. These are promotional starting rates, so confirm the post-promo rate, equipment fees, and any contract before signing; then choose based on the full written cost.
Which is faster for gaming, work from home, and 4K streaming?
Both providers have a 90/100 speed score; Xfinity’s 2,000/2,000 Mbps tier reaches about 100%, while Quantum Fiber’s 2,000/1,000 Mbps tier reaches about 48%. Either listed tier is more than enough for demanding use where available, so check your address and prioritize the upload speed you need.