Two of NZ's biggest broadband providers are the worst performers, says the Commerce Commission.
A report issued yesterday ranked Telecom, Vodafone and smaller company Slingshot the worst performers.
The three companies scored average to below average in tests, including time taken to connect to the internet, download speeds and the time taken to send and receive emails.
By contrast, industry minnows such as MaxNet, Snap and Compass provided good services in their target areas, while the country's second-biggest provider, TelstraClear, rated best in Auckland, Wellington and Christchurch.
In Hamilton and Dunedin, Orcon shared the top spot with TelstraClear.
The quarterly study by analysts Epitiro Technologies and IDC measured 13 internet service providers in 11 sites across the five major cities.
In Auckland, Telecom scored the worst of all internet service providers, followed by Vodafone and Slingshot.
TelstraClear DSL was the city's best provider, scoring 42 per cent better than the Auckland average.
Hamilton emerged as the country's broadband winner, with a service on average 30 per cent better than the rest of the country.
The report was not all bad for the big companies - the writers noted large companies had it tougher than their competition, because of crowded networks. Smaller networks had it easier, with relatively few users at any one time.
Report co-author Mike Cranna said Telecom was partly a victim of its own size.
"When you have 60 per cent of the market, that's an awful lot of customers and an awful lot of network to maintain.
"But we also know that traditionally Telecom has under-invested in its network."
The report said upgrades at key Auckland sites by Telecom, Vodafone, Slingshot and TelstraClear should start to improve broadband services over the rest of the year.
BEST TO WORST
Auckland's broadband providers in order of performance
* TelstraClear DSL.
* Kiwi Online.