Gross profits at the group doubled to £52m in the 12 months to April 30 from £25m the previous year, while revenue hit £93m from £46m over the same period.
However, operating losses hit £21m in 2018, from £5m a year earlier.
The estate agent launched in the US in September 2017, marking its third market after the UK and Australia.
Purplebricks said it has an online market share of 74% in the UK, while revenue in the country increased by 81%.
Group marketing costs in the year increased to £42 from £18m.
Share price fall
Purplebricks share price was down by around 3% in mid-morning trading.
Michael Bruce, group chief executive, said: “We have doubled revenues in tough markets, taking market share as we continue to win over consumers to the modern way of buying and selling property.
“Purplebricks’ goal to build a modern global estate agency business demonstrates unrivalled ambition and, in just four years, huge progress.
“We look forward to the years ahead with excitement and confidence.”
After the year end, the group announced it would expand into Canada with the acquisition of online estate agent DuProprio/ComFree.
Emma-Lou Montgomery, associate director at Fidelity Personal Investing said: “Purplebricks has once again proven that the property market isn’t stagnating, as traditional estate agencies would have us believe.
“House buyers and sellers have simply moved with the times and gone online.
“Claiming a solid 74% share of the online property market, Purplebricks is one to watch.”