Q1
Best network for CB3?
O2 leads with 100/100 — driven by 100% 5G and 100% 4G in this mixed urban-rural part of Cambridge.
CB3 DISTRICT · CAMBRIDGE
Best mobile network in Girton CB3 · Cambridge
O2 scores 100/100 — the best measured network for CB3 in Cambridge, 5 points clear of the weakest. 100% 5G-grade · 100% 4G. Ofcom Mobile Coverage data (May 2025), measured across 108 addresses in 6 sampled postcodes.
The CB3 district covers Girton, Grantchester, Market and Harston. Signal varies street by street — scan your exact postcode below.
RESULT · CB3 · CAMBRIDGE
Coverage for CB3 district
★ BEST MEASURED
O2
100/100
O2 has the strongest measured coverage for the CB3 district in Cambridge, 5 points clear of the weakest network in Ofcom's data.
Full ranking — CB3
#1
O2
#2
Vodafone
#3
Three
#4
EE
Coverage analysis — CB3
Comparing Ofcom-measured operator coverage, O2 delivers the strongest signal in Cambridge. In this mixed urban-rural area, O2 achieves an overall coverage score of 100/100 — driven by excellent 5G coverage (100%) and rock-solid 4G at 100%. 5G and 4G scores are closely matched, reflecting a mature, stable network.
O2 comfortably leads Vodafone by 0 points overall. While Vodafone reaches 100% on 5G and 100% on 4G in Cambridge, it falls short of O2's combined performance across all bands. Three and EE round out the field at 96 and 95 respectively.
Why O2 for CB3?
O2's 5G rollout in Cambridge is among the strongest nationally, covering 100% of premises in the CB3 district. For anyone streaming video, gaming on mobile, or relying on a mobile hotspot at home, this level of 5G penetration makes a real difference to day-to-day speed.
The runner-up in CB3 is Vodafone at 100/100 (100% 5G / 100% 4G). It is a close contest — both operators deliver strong coverage in CB3, and your choice may come down to tariff, handset preference, or existing contract.
Switching to O2 in Girton
O2 has the strongest measured signal here — 100/100, with 100% 5G-grade and 100% 4G coverage across Girton, Grantchester, Market and Harston, 5 points clear of the weakest. A cheaper plan on a network that does not reach your street costs more than it saves, so start from the coverage and pick the plan second.
Some links on this page are affiliate links. If you switch through one we may be paid a commission. It never changes which network we rank first - that comes from Ofcom coverage data alone.
Explore the Cambridge area
View full coverage analysis for the Cambridge (CB) area, or enter any UK postcode in the scanner above for a personalised result.
Coverage FAQ — CB3
Q2
Is 5G available in CB3?
O2 provides excellent 5G coverage at 100%. Vodafone follows at 100%.
Q3
Which network has the best 4G?
O2 leads 4G too at 100%. Reliable 4G is critical in mixed urban-rural areas.
Q4
Is Three worth considering?
Three scores 96/100 in CB3 (100% 5G, 100% 4G). It may suit certain tariff or price preferences despite trailing the top two.