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Contra Costa
Cell coverage comparison in Contra Costa, California
Based on crowdsourced speed tests and signal measurements in Contra Costa, California, the current snapshot reflects over 5,900 speed tests and shows medians of 118.0 Mbps download, 10.5 Mbps upload, and 39 ms latency.
Performance by Carrier in Contra Costa
Explore median download speeds, upload performance, and network latency for each major mobile carrier in Contra Costa, calculated from millions of real-world, crowdsourced speed tests. These results reflect typical everyday performance to help you compare carriers and choose the network that delivers the fastest speeds, most responsive connections, and broadest coverage where you live, work, and travel.
DownDownload74.7 Mbps
UpUpload6.5 Mbps
Reliab.Reliability6.6 / 10
Cov.Coverage98.0%
Over 1,300 tests conducted
DownDownload179.5 Mbps
UpUpload16.7 Mbps
Reliab.Reliability8.8 / 10
Cov.Coverage95.4%
Over 1,000 tests conducted
DownDownload122.5 Mbps
UpUpload11.2 Mbps
Reliab.Reliability8.5 / 10
Cov.Coverage99.2%
Over 3,400 tests conducted
Performance by Carrier shows side-by-side results for the primary mobile providers measured in Contra Costa. Each row reflects download, upload, latency, and reliability for that carrier.
Providers included in this comparison are AT&T, T-Mobile, Verizon. Per-carrier test counts are shown in the table to indicate data accuracy.
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Network Performance in Contra Costa
Get a complete view of mobile network performance across Contra Costa with overall benchmarks and carrier-by-carrier breakdowns. Explore median performance metrics calculated from millions of real-world, crowdsourced speed tests. Start with the Contra Costa-wide snapshot to understand overall network trends, then dive deeper to compare individual carriers side-by-side and see how each performs in speed, responsiveness, and availability.
Median Performance
Download
118.0Mbps
Upload
10.5Mbps
Latency
39ms
Reliability
8.0/ 10
Top Performers
Best Download: T-Mobile
179.5 Mbps
Best Upload: T-Mobile
16.7 Mbps
Best Latency: Verizon
37 ms
Best Reliability: T-Mobile
8.8 / 10
Best Coverage: Verizon
99.2%
Coverage Snapshot
5G94.0%
4G LTE99.4%
Based on over 5,900 speed tests
Network Performance aggregates all measured carriers in Contra Costa to provide a baseline view of typical speeds and latency in the area. Use these medians as a quick indicator of overall network quality.
These medians are calculated from over 5,900 tests. Current medians are 118.0 Mbps download, 10.5 Mbps upload, and 39 ms latency.
Cell Phone Plans Available in Contra Costa
Compare wireless plans from carriers with coverage in this area.
Recommended PlanSponsored
Mint Mobile Unlimited Annual
$30/mo
12 month term
T-Mobile
- Unlimited Datahigh-speed
- 20 GB Hotspot
- Unlimited Minutes
- Unlimited Texts
Limited-time offer
$15/mo first year today
Recommended Plan
Red Pocket Premium
$30/mo
Monthly plan
AT&T
- 50 GB Datahigh-speed, then 64Kbps
- 10 GB Hotspot
- Unlimited Minutes
- Unlimited Texts
Recommended Plan
Mint Mobile 15GB 3 Months
$35/mo
3 month term
T-Mobile
- 15 GB Datahigh-speed, then 128Kbps
- Hotspot Included
- Unlimited Minutes
- Unlimited Texts
Red Pocket 500MB 12 Months
$5/mo
12 month term
AT&T
- 0.5 GB Datahigh-speed, then Unknown
- Hotspot Included
- 500 Minutes
- 500 Texts
Tello 100 Mins
$5/mo
Monthly plan
T-Mobile
- No Data Included
- No Hotspot Included
- 100 Minutes
- Unlimited Texts
Tello 1GB 100 Mins
$6/mo
Monthly plan
T-Mobile
- 1 GB Datahigh-speed, then data stops
- Hotspot Included
- 100 Minutes
- Unlimited Texts
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Citys in Contra Costa
Select a city to view coverage data for that location.
Cell Coverage in Contra Costa: FAQ
What is the best cell phone carrier in Contra Costa?
Based on crowdsourced speed tests in Contra Costa, T-Mobile currently leads in median download speeds. Compare carriers in the performance table above for the latest results.
Why might this page show limited data for Contra Costa?
We need at least 25 recent speed tests to generate reliable local metrics. If we don't have enough tests yet, the page focuses on maps and nearby locations while we keep collecting data.
What is the reliability score?
The reliability score summarizes how dependable mobile performance is in Contra Costa. It uses a 0.0 to 10.0 scale (higher is better) and is calculated from real-world speed test percentiles with weighted components: download (50%), latency (30%), and upload (20%). It evaluates the lower-end experience using the bottom 10%, 5%, and 1% percentiles when enough samples are available. If local speed testing is limited, a coverage-based fallback is used from signal quality distribution (great/good/poor).
How can I check coverage at my specific address in Contra Costa?
Use the interactive map to check signal strength at your exact address. Visit the CoverageMap interactive map to explore 4G/5G availability.
How can I contribute coverage data for Contra Costa?
Download the CoverageMap app and run a few speed tests with location enabled. Your results help improve coverage accuracy and unlock local rankings faster.
Get the appView Coverage Map for Contra Costa
Explore detailed coverage data on our interactive map to find the best carrier for your specific location.
Open Interactive Map