CityFibre Speed Test Guide (2026)

CityFibre is a wholesale full fibre network — not a retail broadband provider — serving over 4.5 million UK premises across 95+ towns and cities. You cannot buy broadband from CityFibre directly. Instead, retail ISPs including Vodafone, TalkTalk, Zen Internet, and Cuckoo sell packages over the CityFibre network, delivering symmetric speeds up to 910Mbps or more depending on the ISP's package. If you are on a CityFibre-backed plan, speeds and support come from your chosen ISP, not CityFibre.

Which ISPs Use CityFibre and What Speeds Do They Offer?

CityFibre's XGS-PON network is capable of multi-gigabit speeds — up to 5.5Gbps in laboratory tests — but retail packages from ISPs typically offer up to 910Mbps or 2.2Gbps. Vodafone uses CityFibre to deliver its Full Fibre 74, 150, 500, and 910Mbps packages, plus a 2.2Gbps Pro Xtra tier in select areas, with prices from around £23–£30 per month. TalkTalk offers Full Fibre 150, 500, and 900Mbps on CityFibre from £24 per month. Zen Internet provides Full Fibre 100, 500, and 900Mbps on CityFibre from around £30 per month, with full symmetric upload speeds. Cuckoo is primarily a CityFibre ISP, offering 150, 500, and 900Mbps packages with fully symmetric uploads. A key advantage of CityFibre over Openreach FTTP is that many ISPs offer symmetrical speeds — meaning upload speeds match download speeds — which is valuable for remote workers and content creators. CityFibre's network passes over 4.7 million premises as of 2026.

How to Run a Speed Test on a CityFibre Connection

To get an accurate reading of your CityFibre connection, connect your device directly to your ISP-provided router using an ethernet cable. On CityFibre packages at 500Mbps or above, ensure the ethernet port on your device is Gigabit-capable (1Gbps) or faster — a 100Mbps fast ethernet port will cap your result at 94Mbps regardless of your subscription speed. If testing Vodafone's 2.2Gbps Pro Xtra package, you will need a 2.5Gbps or faster ethernet port. Close all background applications and pause any active downloads or streams before starting. Run the test three or more times and note the average and range. Because CityFibre's network delivers symmetric speeds, your upload figure should closely match your download figure on a correctly set-up connection — a large gap between download and upload can indicate a misconfigured router or an ONT (optical network terminal) issue. Contact your ISP's technical support team if this occurs.

Understanding Your CityFibre Speed Test Results

CityFibre's full fibre infrastructure typically produces excellent performance across all four key metrics. Download speed (Mbps) determines how quickly content arrives at your device. On CityFibre, upload speed should be nearly equal to download on symmetric plans — a distinctive advantage over Openreach FTTP, where uploads are a fraction of download speeds. Latency (ping) on CityFibre connections is typically 5–15ms to UK servers, with user reports of 2–9ms on ethernet in uncongested conditions. Jitter on a well-configured CityFibre connection should be under 5ms, making it well-suited to real-time applications like gaming, video calls, and VoIP. If your download is consistently more than 20% below the minimum guaranteed speed stated by your ISP, raise a complaint through your ISP's process — not with CityFibre directly. CityFibre operates the wholesale layer only; all customer support is handled by the retail ISP you signed up with.

How to Improve Your Speeds on a CityFibre Network

Router placement and hardware capability are the main limiters on a CityFibre connection, where the underlying fibre network is rarely the bottleneck. Position your router centrally, away from other electronic devices, and use the 5GHz or Wi-Fi 6 band for close-range devices. Ethernet is essential for testing and for achieving maximum speeds — most Wi-Fi connections cannot deliver more than 600–900Mbps even under ideal conditions. If your ISP provided a router with a 1Gbps WAN port, this will cap speeds at around 940Mbps regardless of your subscription. Vodafone provides a Super Router with a 2.5Gbps WAN port for its higher-speed packages. Zen Internet and Cuckoo also provide capable routers for their CityFibre packages. If your ONT (the small white box installed during your CityFibre activation) is showing a flashing red light, this indicates a physical fibre fault — contact your ISP immediately, as this cannot be resolved by adjusting router settings.

Compare Broadband Deals at Your Address

If CityFibre infrastructure passes your street, you may have access to several competing ISPs offering symmetrical gigabit speeds. Use CompareFibre to check which providers — including Vodafone, TalkTalk, Zen Internet, and Cuckoo — are available at your postcode and compare their current pricing and contract terms.

Frequently Asked Questions

Can I buy broadband directly from CityFibre?

No. CityFibre builds and operates the wholesale fibre network but does not sell broadband directly to consumers. You must sign up with a retail ISP that uses the CityFibre network, such as Vodafone, TalkTalk, Zen Internet, or Cuckoo. Check your postcode to see which of these ISPs are available in your area.

Are CityFibre speeds symmetrical?

Many CityFibre ISPs offer symmetrical speeds, meaning upload equals download. This is possible because CityFibre's XGS-PON network supports full-duplex transmission. However, ISPs may choose to offer asymmetric packages. Cuckoo offers fully symmetric speeds on its CityFibre plans. Vodafone's Full Fibre 910Mbps plan also delivers near-symmetric uploads at around 910Mbps on CityFibre.

What latency should I expect on a CityFibre connection?

CityFibre full fibre connections typically deliver latency of 5–15ms to UK servers, with some users reporting 2–9ms on ethernet in uncongested conditions. This compares favourably with Openreach FTTC (20–40ms) and is ideal for gaming, VoIP, and real-time video conferencing.

Related Guides

CityFibre Fibre Broadband Deals · Vodafone Fibre Speed Test · TalkTalk Fibre Broadband · Openreach and CityFibre Guide · Broadband Speed Guide

Methodology

This guide is based on publicly available data from Ofcom, provider websites, and independent sources including ISPreview.co.uk, Thinkbroadband, and Point Topic. Pricing, speeds, and availability were verified in April 2026 and are subject to change. CompareFibre is editorially independent — providers do not pay for placement or influence our recommendations.