O2 coverage checker: signal and 5G data for the UK
O2 (operated by Telefónica UK) covers more than 99% of the UK population outdoors on 4G and is the host network for giffgaff, Sky Mobile and Tesco Mobile. It performs strongly in urban areas and city centres and maintains solid indoor signal. Enter your postcode above to see O2's signal scores alongside EE, Vodafone and Three.
How good is O2 coverage in the UK?
O2 delivers strong outdoor 4G coverage across the UK, particularly in cities, commuter towns and suburban areas. Its indoor signal is competitive with EE in most locations. O2 participates in the Shared Rural Network programme, improving rural coverage in underserved areas. For commuters and city-based users O2 consistently ranks among the top two networks for reliable everyday signal.
O2 scores 85/100 for outdoor 4G (2nd of the four networks), 71/100 indoors, 60/100 for outdoor 5G, 82/100 for video calls and 81/100 for streaming.
Does O2 have good 5G?
O2 launched 5G in October 2019 and has rolled it out across all major UK cities and many large towns. It uses 3.5 GHz mid-band spectrum for faster urban 5G and 700 MHz low-band for wider geographic reach. Its 5G availability sits broadly in line with EE nationally — ahead of Vodafone in most areas and behind Three in some dense urban centres.
O2's outdoor 5G score is 60/100 — 4th of the four networks for 5G availability. 5G availability is strongest in major cities; suburban and rural areas typically fall back to 4G. Check your postcode above for the exact O2 5G score at your address.
Where is O2 the best network?
O2 is the best network in 3 of 100 UK postcode districts measured here. O2's strongest region is Greater Manchester, where it leads in 1 district. O2's top-scoring district is Didsbury (M20) at 79/100.
Strongest regions
How does O2 compare with EE, Vodafone, Three?
O2 ranks 2nd of the four networks overall (composite score 76/100). ↑ marks the leader on each metric.
| Metric | EE | O2 ★ | Vodafone | Three |
|---|---|---|---|---|
| Outdoor 4G | 88↑ | 85 | 83 | 78 |
| Indoor 4G | 74↑ | 71 | 69 | 64 |
| Outdoor 5G | 68 | 60 | 65 | 72↑ |
| Video Calls | 86↑ | 82 | 80 | 75 |
| Streaming | 85↑ | 81 | 79 | 77 |
Scores out of 100. ↑ marks the leader on each metric. ★ marks O2.
Which networks use O2?
Three widely-used MVNOs run on O2: giffgaff, Sky Mobile and Tesco Mobile. All three share O2's 4G coverage. giffgaff offers flexible no-contract SIMs; Sky Mobile includes monthly data rollover; Tesco Mobile integrates Clubcard points. This makes O2 the parent network behind the UK's most popular budget mobile brands.
How does O2 compare with EE, Vodafone and Three?
O2 ranks second nationally for outdoor 4G coverage behind EE. For 5G it sits in the middle of the four networks. Its MVNO ecosystem is its biggest advantage: if you want O2-class coverage at a lower price, giffgaff or Tesco Mobile are natural alternatives. O2 also offers Priority rewards — regular perks and presale tickets exclusive to direct O2 customers.
Is O2 good for indoor signal?
O2 scores 71/100 for indoor 4G — 2nd highest of the four networks. Indoor scores are lower than outdoor for every UK network: O2's indoor score is 14 points below its outdoor 4G score of 85. EE (74) scores higher; Vodafone (69) and Three (64) score lower.
How we measure O2 coverage
Coverage scores for O2 come from Ofcom signal measurement data aggregated across UK postcode districts. Each network receives five scores out of 100: outdoor 4G, indoor 4G, outdoor 5G, video calls and streaming. The overall score weights outdoor 4G at 30%, indoor 4G at 20%, outdoor 5G at 20%, video calls at 15% and streaming at 15%. Scores of 80 and above are rated excellent, 67–79 good, and below 67 fair.
Full methodology → How it worksFrequently asked questions
Is O2 a good network in the UK?
O2 is the UK's second-strongest network for outdoor 4G nationally. It performs particularly well in cities and suburban areas and hosts three of the UK's most popular budget brands: giffgaff, Sky Mobile and Tesco Mobile.
Does giffgaff use O2?
Yes. giffgaff is an MVNO that runs entirely on O2's network. giffgaff customers get the same 4G coverage as O2 customers at every UK location.
Which networks run on O2?
giffgaff, Sky Mobile and Tesco Mobile all use O2's network infrastructure. They share O2's 4G masts and coverage footprint — the differences are pricing and extras, not signal.
Does O2 have 5G?
Yes. O2 launched 5G in 2019 and covers all major UK cities. Enter your postcode above to see the 5G score for your area.
Is O2 better than Three?
O2 scores higher for overall 4G coverage breadth and rural reach nationally. Three leads in some urban areas for 5G data speeds and spectrum depth. Check your postcode above to compare them at your specific location.
Check O2 at your postcode
National scores are averages. Actual signal can vary by street.
Enter your postcode