That's according to a new report by wireless mapping company OpenSignal, which compared the performance of Australia's three largest telcos based on 15 million data samples crowdsourced from 7904 users.

The results show Telstra leading the pack for 4G speeds, with average downloads of 23.6 megabits per second, as well as overall speeds, averaging 17.1 Mbps across both 3G and 4G networks.

Optus and Vodafone were tied on 4G speeds, both averaging about 19 Mbps during the test period from February 1 to April 30 this year.

The study found all three telcos had effectively the same 3G speeds of about 4 Mbps.

One surprise the study threw up was how often customers could connect to the 4G network instead of being stuck on the slower 3G.

It found that customers of both Telstra and its smaller competitor Vodafone could access 4G about 77 per cent of the time. Optus customers could connect to 4G about 73 per cent of the time.

The result is a big turnaround for Vodafone, which just four years ago was dubbed "Vodafail" and suffered an exodus of customers because of poor network coverage.

It will also come as good news for Telstra, which has suffered its own string of embarrassing network outages to both its fixed line and mobile data services this year.

The final metric tracked was the telcos' response times, known as "latency", which has become an important performance measure as all three start moving voice calls onto their 4G LTE networks, the report says.

Vodafone had the best latency on 3G, while Vodafone and Optus drew on 4G.

OpenSignal monitors the data connections of telco users who have downloaded its app.

The company says this gives a more accurate picture of network performance over drive-test of user-initiated simulations, but the report - it's first on Australia - does not say how geographically widespread the data sample was.