Hong Kong’s regulator reports a 5G coverage figure above 99.0% of the population, the result of an outdoor-driven rollout that began in April 2020. That headline number does not describe the experience users have indoors, where Hong Kong residents spend more than 85% of their day. The territory packs roughly 7.5 million people into a built-up footprint on about a quarter of its land area, and it holds the world’s largest portfolio of completed buildings 150 meters or taller. Indoor conditions define the network experience in Hong Kong, and they diverge sharply from the outdoor picture. Speedtest Intelligence® indoor data gathered from buildings across the territory during 2025 takes the analysis past the outdoor coverage benchmark and into the buildings where most of Hong Kong’s mobile use actually happens.
Key Takeaways
- An elevenfold 5G performance gap separates Hong Kong’s slowest buildings from its fastest, and geography explains little of it. Combined across the four major operators, the median 5G download speed across measured buildings is 167.37 Mbps. An elevenfold gap separates the slowest 10 percent of buildings (43.02 Mbps) from the fastest 10 percent (479.97 Mbps). Within every region, the fastest 10 percent of buildings outpace the slowest 10 percent by at least sevenfold, so the divide tracks individual buildings and their infrastructure rather than districts.
- Indoor 5G coverage is nearly universal but weaker than outdoor benchmarks suggest. The average 5G Synchronization Signal Reference Signal Received Power (5G SS-RSRP) across measured buildings registers -89.5 dBm for the four major operators. This value sits on the borderline between good and fair coverage, and 44.8% of buildings fall into the fair range. Coverage reach matters less for speed than deployment intensity and capacity additions, which separate fast buildings from slow ones.
- Shared in-building infrastructure delivers consistent performance across operators while private venues create single-operator advantages. All four operators deliver strong 5G performance at high-traffic landmarks where samples from all operators are available, such as Hong Kong International Airport Terminal 1 and the Hong Kong Convention and Exhibition Centre. Among the 16 venues we examined individually, the gap between the best and worst operators reaches 80-fold within the same building in private estates and towers, where indoor coverage depends on a single operator’s in-building investment.
- Hong Kong’s four major mobile operators display highly distinct indoor performance profiles. csl delivers the strongest signal in 46.0% of measured buildings, while China Mobile Hong Kong leads at international gateways. 3 Hong Kong tops the convention center and East Point City. SmarTone achieves the highest median download speeds across the majority of the 16 selected venues.
Hong Kong is the world’s densest skyscraper city, and its residents spend most of the day inside
Hong Kong packs 7.5 million residents into approximately a quarter of its available land mass, creating an ultra-dense vertical environment. The CTBUH Skyscraper Center recorded 669 completed buildings of 150 meters or taller as of January 2025, placing the territory ahead of Shenzhen and other global hubs. Population density reaches roughly 59,000 residents per square kilometer in districts like Kwun Tong, according to data from the Census and Statistics Department. A 2018 exposure study published in the Journal of the Air & Waste Management Association indicates that residents spend 85% of their daily lives indoors.
In its Trading Fund Report 2024/25, the Office of the Communications Authority (OFCA) stated that 5G population coverage exceeded 99% by the end of March 2025. However, this metric only tracks outdoor detectability, which fails to reflect indoor network performance. Mid-band and high-band 5G frequencies suffer severe attenuation when passing through the reinforced concrete and tinted low-E glass of modern high-rises. Consequently, outdoor statistics offer very little insight into network quality inside buildings, where the vast majority of mobile traffic originates.
Indoor 5G performance spreads more than elevenfold across Hong Kong’s buildings
We analyzed indoor 5G performance across more than 760 buildings in Hong Kong using Speedtest Intelligence data from 2025, spanning shopping malls, residential estates, offices, transit hubs, and hotels with enough samples for a stable reading. We looked at the combined median 5G download and upload speeds across all operators and averaged their 5G signal strength, so the numbers reflect what would typically be the experience inside the building, whichever network they subscribe to.
The overall data reveals solid baseline performance, with an all-operator median download speed of 167.37 Mbps and an upload speed of 27.98 Mbps. This performance comfortably exceeds requirements for applications like standard HD video calls via Microsoft Teams and 4K Netflix streaming. However, the aggregate medians mask large indoor performance disparities. An elevenfold gap separates the slowest 10% of buildings (43.02 Mbps) from the fastest 10% (479.97 Mbps). Upload performance shows even greater variance, nearly fifteenfold from 5.35 Mbps at the 10th percentile to 79.04 Mbps at the 90th percentile, leaving limited headroom for sustained high-definition upstream traffic in lower-performing locations.
Analysis of regional data reveals that the territory’s densest urban cores do not necessarily deliver the fastest speeds. The new-town areas of Sha Tin and Ma On Shan lead the territory with a combined median download speed of 189.72 Mbps, closely followed by Tseung Kwan O at 189.66 Mbps. Although Kowloon accounts for the largest volume of 5G samples, it ranks near the bottom with a median download speed of 157.07 Mbps. This pattern suggests that more modern buildings are equipped with newer in-building infrastructure.
Regional download medians remain tightly clustered, with median download speed ranging from 128.59 Mbps in the Airport and North Lantau region to 189.72 Mbps in Sha Tin and Ma On Shan. Upload rankings shift the order slightly, as Hong Kong Island leads the territory with a median upload speed of 31.58 Mbps despite placing third for download performance. The elevenfold performance gap repeats within every single region, and building-level speeds spread at least sevenfold between the fastest and slowest 10% of buildings in each district. This means that two buildings on the same street could report wider performance variations than when comparing two regional medians.
Assessing the average 5G signal strength across every measured building for all providers reveals a mixed picture. The territory-wide average 5G SS-RSRP across all operators sits at -89.5 dBm, placing it between good and fair coverage. Only 4.2% of buildings achieve an average signal strength stronger than -80 dBm. Good signal quality appears in just over half of the venues (50.5%), while 44.8% sit in the fair range between -90 dBm and -100 dBm. Fewer than 1.0% of the sampled buildings average a poor signal strength below -100 dBm, where throughput drops and disconnections become highly probable. Operators must deploy dedicated internal systems to bridge this gap, as relying on outdoor coverage alone cannot overcome the physical attenuation caused by modern building materials.
Shared infrastructure delivers consistent performance while private venues create single-operator advantages
Territory-wide medians describe Hong Kong’s broad indoor 5G picture, but they obscure the severe performance gaps between individual buildings. To understand this localized experience, we selected 16 prominent buildings that recorded enough samples for stable operator-level readings and span the high-traffic indoor environments where residents spend their time. These categories include shopping malls, residential complexes, commercial office towers, convention venues, and transit hubs.
Granular analysis of the 16 selected buildings highlights the differences in coverage and performance between real estate environments. The signal strength readings separate these locations into two clear categories based on infrastructure ownership. Operators display tight performance clustering at high-traffic landmarks served by shared multi-operator systems. The Hong Kong Convention and Exhibition Centre (HKCEC) New Wing, for example, maintains median 5G SS-RSRP readings between -72 dBm and -75 dBm across all four networks, and similarly tight readings appear at Hong Kong International Airport (HKIA) Terminal 1 and AsiaWorld-Expo.
Operators’ results diverge dramatically in locations without shared infrastructure systems. SmarTone registers a strong reading of -71 dBm at East Point City, representing the most powerful single-operator signal in the selection. csl drops to -97 dBm within the same building, creating a 26 dB variance. The 5G Synchronization Signal Reference Signal Received Quality (5G SS-RSRQ) stays consistent between -10 dB and -14 dB across all networks and locations, indicating that infrastructure deployment drives the performance gap rather than cellular interference.
All four major operators demonstrate uniform download performance at locations utilizing shared indoor infrastructure. For instance, download speeds across all providers at the HKCEC New Wing fell tightly within a range from 235.69 Mbps to 333.76 Mbps. Similarly, at HKIA Terminal 1, even the lowest recorded performance among the operators remains robust with a median download speed of 196.49 Mbps. In contrast, performance in private commercial and residential buildings depends heavily on which operator installed the distributed antenna system. This often results in sharp disparities where one operator thrives while others struggle. For instance, at Park Central, SmarTone reaches 906.55 Mbps, while China Mobile Hong Kong drops to 11.27 Mbps. Similarly, at APM Millennium City V, SmarTone hits 586.82 Mbps compared to csl’s 35.87 Mbps, though roles reverse at Metro City Plaza II, where csl leads with 834.86 Mbps. Building characteristics also play a role. Extreme height, for example, can limit performance, as seen at Central Plaza (374m) and Two IFC (412m), where all operators fall below 90 Mbps, while moderate-height structures like Three Exchange Square (144m) can support much higher speeds of up to 488.97 Mbps.
Physical architecture and commercial dynamics create these distinct performance outcomes. Modern energy-efficient glass and heavy reinforced concrete shield building interiors from external macro cell sites, making dedicated in-building distributed antenna systems or small cells essential for good indoor connectivity. A shared multi-operator deployment led by the MTR Corporation demonstrates the consistent performance that shared infrastructure provides across transit stations. Policymakers introduced the Telecommunications (Amendment) Ordinance 2024 to grant operators statutory access to designated mobile infrastructure space in newly approved buildings starting in April 2025 without charging access fees. This new regulation highlights how the previous market-led approach resulted in a two-tier experience: while public transit hubs benefit from shared, reliable access, private buildings remain reliant on the performance of a single operator.
Four operator profiles highlight the opportunity to improve indoor customer experience through shared systems
With total mobile subscriber penetration exceeding 440% as of February 2026, per OFCA Mobile Service Statistics, Hong Kong’s four major 5G operators compete in a saturated market, and the indoor data gives each a distinct profile rather than a single ranking.
Strongest 5G Signal Share Across Hong Kong’s Measured Indoor Buildings
Source: Speedtest Intelligence® | 2025
csl reaches furthest. It delivers the strongest 5G signal in 46.0% of measured buildings, more than the other three combined, while operating Hong Kong’s largest subscriber base per HKT’s financial results, and it posts one of the sample’s fastest venue readings at Metro City Plaza II, 834.86 Mbps.
China Mobile Hong Kong leads at international transport gateways. The operator captures the top median download speed at both major arrival points, delivering 512.65 Mbps at HKIA Terminal 1 and 337.28 Mbps at AsiaWorld-Expo. It records the second-broadest signal reach by leading in 20.0% of measured buildings, and it claims five upload speed leads out of the 16 selected venues. The company maintains an upload baseline above 60.00 Mbps across major exhibition spaces and the airport, matching the demands of its large mainland-visitor subscriber segment.
3 Hong Kong clusters its network resources for performance at specific high-value venues. The carrier leads the HKCEC New Wing with a median download speed of 333.76 Mbps and tops East Point City at 685.45 Mbps, even though SmarTone holds the stronger signal there. SmarTone leads the most venues, recording the highest median download in 10 of the 16 buildings. At three Sun Hung Kai Properties venues, the lead comes with a signal advantage of up to 12 dB, consistent with dedicated in-building deployment.
Shared infrastructure delivers more uniform performance
A clear pattern emerges from these four operational profiles: when indoor infrastructure is shared, all operators provide a uniform and strong user experience. Conversely, in the absence of shared infrastructure, the indoor experience depends on each operator’s specific building-by-building investment choices, giving a distinct advantage to whichever operator has deployed its own in-building systems.
Hong Kong features a dense vertical topology, a regulatory framework that now mandates shared in-building access in newly approved buildings, and a clear elevenfold performance gap between buildings. Resolving this discrepancy is an investment decision executed building by building. The high-traffic venues where all four operators committed capital show that shared indoor deployment delivers results.
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