CM21 broadband and area guide
Ofcom coverage, connection speeds, house prices and local data for 310 postcodes across 2 sectors in East Hertfordshire.
Full fibre
0%
Gigabit
70%
Superfast
94%
Postcodes
310
CM21 covers 310 postcodes in East Hertfordshire. Superfast reaches 93.6%, with gigabit available to 69.5%.
Broadband speeds in CM21
Share of CM21 premises by the fastest download speed available, averaged across all 310 postcodes in the district.
Superfast coverage spans 93.6% of premises. Gigabit services reach 69.5%, with ultrafast at 71.2%, indicating a small proportion at 1.7% on fibre-to-the-cabinet without gigabit speeds. The speed distribution shows 71.2% at 300 Mbps and above, with 22.4% on 30-300 Mbps. Below-USO premises are at 0% coverage. Only 1.7% sit below 10 Mbps, indicating strong underlying infrastructure. Cable gigabit coverage is solid across this suburban district. Most premises have access to good speeds. The remaining postcodes fall back to reliable superfast services.
Source: Ofcom Connected Nations. Percentages are district-wide averages of postcode-level availability, so rows may not sum to exactly 100%.
Connectivity in detail
Below 10 Mbps USO
0%
Premises unable to get the 10 Mbps universal service minimum
Fixed wireless
0%
Premises that can use a fixed wireless access service
Broadband by sector
CM21 splits into 2 postcode sectors. Coverage and prices can differ street by street, so open a sector below to find your exact postcode.
| Sector | Postcodes | Superfast | Full fibre | Gigabit |
|---|---|---|---|---|
| CM21 0 | 136 | 91% | 0% | 67% |
| CM21 9 | 174 | 96% | 0% | 72% |
All CM21 0 postcodes (136)
All CM21 9 postcodes (174)
Best deals
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Living in East Hertfordshire
CM21 is solidly connected with cable gigabit reaching roughly two-thirds of premises. The remaining third on superfast speeds are adequately served.
Remote worker score
54/100
Connectivity and amenities for home working
Family score
50/100
Schools, safety and family amenities
Value score
50/100
What you get for the local price level
CM21 broadband FAQs
How does gigabit availability here compare to the surrounding area?
At 69.5%, coverage is solid and reflects moderately developed cable infrastructure across the district.
What's the speed experience for non-gigabit premises?
About 22% access superfast speeds, adequate for most household uses.
Is below-USO coverage a concern?
No; zero postcodes fall below USO standards, indicating universal adequate coverage.
Will broadband speeds improve further?
Cable gigabit deployment here appears mature; major future improvements would require fibre-to-the-premises investment.
Neighbouring districts
Check your exact postcode
Every postcode in CM21 has its own page with broadband speeds, house prices, school ratings and crime stats. You can also compare providers for your address.
Data sources: Broadband data from Ofcom Connected Nations 2025 · House prices from HM Land Registry · Crime from Police.uk · See all data sources