Q1
Best network for CF3?
EE leads with 100/100 — driven by 100% 5G and 100% 4G in this densely populated urban part of Cardiff.
CF3 DISTRICT · CAERPHILLY
Best mobile network in Rudry CF3 · Caerphilly
EE, O2, Three and Vodafone all score 100/100 in CF3 — no network wins here on coverage. 100% 5G-grade · 100% 4G. Ofcom Mobile Coverage data (May 2025), measured across 132 addresses in 6 sampled postcodes.
The CF3 district covers Rudry, Rumney, Llanrumney and Marshfield, in Caerphilly. Signal varies street by street — scan your exact postcode below.
RESULT · CF3 · CARDIFF
Coverage for CF3 district
✓ ALL FOUR MEASURE THE SAME
All four networks
100/100
Ofcom measures all four networks identically in the CF3 district, so coverage is not the thing to choose on here. Compare price and contract length instead.
Full ranking — CF3
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EE
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O2
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Three
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Vodafone
Coverage analysis — CF3
No network wins Cardiff on coverage. All four score identically in Ofcom's measurements, across 132 addresses sampled in 6 postcodes. On a difference that small, EE, O2, Three and Vodafone will all work here — so choose on price, contract length and roaming, not on a coverage map. Coverage only becomes the deciding factor once you leave built-up areas, and it still varies street by street indoors: check your own postcode below to see the measurement for your address rather than for Cardiff as a whole.
Ranked by Ofcom's overall score: EE 100, O2 100, Three 100, Vodafone 100. The spread between best and worst is 0 points, which is inside the margin where a coverage figure stops being a useful tiebreak. Ofcom's data describes outdoor signal across sampled addresses; it cannot tell you how any of them behave inside your own building.
Why EE for CF3?
EE's 5G rollout in Cardiff is among the strongest nationally, covering 100% of premises in the CF3 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 CF3 is O2 at 100/100 (100% 5G / 100% 4G). It is a close contest — both operators deliver strong coverage in CF3, and your choice may come down to tariff, handset preference, or existing contract.
Choosing a network in Rudry
Every network reaches Rudry, Rumney, Llanrumney and Marshfield to the same standard in Ofcom's data, so coverage cannot pick one for you here — price and contract length can. Compare what each is charging, then check the exact street you live on before you commit, because indoor signal still varies where the area figures match.
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 Cardiff area
View full coverage analysis for the Cardiff (CF) area, or enter any UK postcode in the scanner above for a personalised result.
Coverage FAQ — CF3
Q2
Is 5G available in CF3?
EE provides excellent 5G coverage at 100%. O2 follows at 100%.
Q3
Which network has the best 4G?
EE leads 4G too at 100%. Reliable 4G is critical in densely populated urban areas.
Q4
Is Three worth considering?
Three scores 100/100 in CF3 (100% 5G, 100% 4G). It may suit certain tariff or price preferences despite trailing the top two.