Full-Fibre vs Gigabit-Capable Broadband Explained
Ofcom uses several overlapping categories to describe broadband capability. This guide explains what each label means, how they relate to each other, and why the distinction matters when comparing local authority and constituency data.
In numbers
Across the UK, 85.9% of premises are gigabit-capable but only 77.5% have true full-fibre — a 8.4pp gap filled almost entirely by upgraded cable networks, not fibre to the door.
The Four Tiers, by UK Coverage
Each tier is a superset of the one below it: nearly every premises has superfast, but only those with a fibre line to the door count as full-fibre. The gap between gigabit-capable and full-fibre is the share served by upgraded cable rather than fibre.
UK premises-weighted coverage by technology tier — Ofcom Connected Nations 2025
The Technology Tiers
UK broadband terminology can be confusing because the same words are used loosely in advertising but precisely in Ofcom's regulatory reporting. PlainBroadband uses Ofcom's exact definitions throughout. Here is what each category means:
Full-Fibre (FTTP — Fibre to the Premises)
Full-fibre means that a fibre-optic cable runs all the way from the telephone exchange or street cabinet to the wall of the building. There is no copper segment at all in the final connection. This architecture is also known as FTTP (Fibre to the Premises) or, in some contexts, FTTH (Fibre to the Home).
Because light travels through fibre without the signal degradation that affects copper wire, full-fibre connections can support symmetrical gigabit speeds regardless of how far the premises is from the exchange. A full-fibre connection in a rural village 10 km from the exchange performs identically to one in a city centre 500 metres away. This symmetry — equal upload and download speeds — also matters increasingly for video conferencing, cloud backup, and working from home.
On PlainBroadband, the full_fibre_pct figure for any local authority or constituency shows what percentage of premises have full-fibre infrastructure passing their building. It does not show what percentage have subscribed.
Gigabit-Capable Broadband
Gigabit-capable broadband is a broader category than full-fibre. It covers all fixed-line broadband infrastructure capable of delivering speeds of at least 1 Gbit/s (1,000 Mbit/s) to a premises. Two main technologies qualify:
- Full-fibre (FTTP): Always gigabit-capable.
- Upgraded cable (DOCSIS 3.1): Cable networks, primarily operated by Virgin Media O2 in the UK, have been upgraded to support gigabit speeds using the DOCSIS 3.1 standard. These use a combination of fibre and coaxial cable to the building rather than pure fibre, but can still deliver gigabit-level performance.
Because every full-fibre connection is gigabit-capable but not every gigabit-capable connection is full-fibre, the gigabit-capable figure for any local authority is always equal to or higher than the full-fibre figure. The gap between the two numbers tells you how much of the gigabit coverage in that area comes from cable networks rather than full-fibre.
In areas with strong Virgin Media presence — typically urban England — you will see notable gaps between the gigabit and full-fibre figures. In rural Scotland or Wales, where Virgin Media has little or no footprint, the two figures are often very close.
Superfast Broadband (SFBB, ≥30 Mbit/s)
Superfast broadband is Ofcom's term for any fixed connection capable of at least 30 Mbit/s download. This covers most fibre-to-the-cabinet (FTTC) deployments — the most common broadband technology in the UK, where fibre runs from the exchange to a street cabinet, and then copper carries the signal the final distance to the home. It also includes upgraded cable networks and full-fibre.
Superfast was the UK government's headline broadband connectivity target through the 2010s. By the time of Ofcom's 2025 report, national superfast coverage had reached well above 95% — the remaining gaps are concentrated in the most rural and remote communities. As a result, superfast coverage figures are high across most of the UK and are less useful for distinguishing modern connectivity than the full-fibre or gigabit-capable figures.
Ultrafast Broadband (UFBB, ≥300 Mbit/s)
Ultrafast broadband is any infrastructure capable of delivering at least 300 Mbit/s. In practice this encompasses full-fibre networks and the most modern cable deployments. Ultrafast coverage sits between superfast and gigabit-capable in the hierarchy, and is less commonly cited than the other tiers.
The Nesting Relationship
The four tiers nest inside each other in coverage terms:
- Gigabit-capable ⊇ Ultrafast ⊇ Superfast
- Full-fibre ⊆ Gigabit-capable
- All full-fibre is also gigabit-capable, ultrafast, and superfast
What this means practically: if you see a local authority with 80% gigabit-capable coverage and 60% full-fibre coverage, approximately 20% of premises have gigabit-capable cable (Virgin Media or similar) but not full-fibre. The remaining 20% not in either category are served by slower infrastructure such as FTTC copper or — in the most remote areas — satellite or fixed wireless access.
Why Does This Distinction Matter?
For most consumer broadband needs today, a gigabit-capable cable connection performs comparably to a full-fibre connection. The practical differences emerge over the longer term. Full-fibre is considered the most future-proof infrastructure because:
- Fibre has essentially unlimited theoretical bandwidth — the same cable can be upgraded to multi-gigabit speeds simply by changing the electronics at each end, without any physical rebuild.
- Fibre is unaffected by electromagnetic interference from adjacent cables, thunderstorms, or nearby electrical equipment.
- Symmetrical upload speeds (equal upload and download) are standard on full-fibre, which matters for video calls, cloud storage uploads, and working from home.
- Cable networks, whilst capable of gigabit downloads, typically offer asymmetric speeds — faster downloads than uploads — and share capacity among neighbours in a street or block.
Policymakers and Ofcom increasingly treat full-fibre as the gold standard for future connectivity. The UK government's Project Gigabit programme funds full-fibre build-out specifically — not cable upgrades — in commercially unviable areas.
What Full-Fibre Take-Up Shows
Ofcom's full-fibre take-up figure — visible in PlainBroadband's rankings and local authority data — measures the proportion of all premises in an area that have actually subscribed to a full-fibre service, not just those that can access one. Take-up depends on how long full-fibre has been available (newer networks have lower take-up), local demographics, awareness, and the pricing strategies of operators.
Low take-up in a high-coverage area can indicate an opportunity: the infrastructure is in place, but residents have not yet switched from legacy copper or cable contracts. Operators and councils sometimes run take-up campaigns to accelerate subscription growth, which in turn improves the commercial case for extending infrastructure further.
How These Terms Appear on PlainBroadband
Every local authority page and constituency page on PlainBroadband shows all four coverage tiers plus the USO gap figure. The rankings page lets you sort across all 361 local authorities by any metric to see where each area stands relative to the national picture. The comparison tool lets you place two local authorities side by side across all metrics simultaneously.
Related: Understanding UK Broadband Coverage | Our Methodology | Rankings