The proportion of top A-level grades in England, Wales and Northern Ireland has fallen since 2021, but remains higher than in 2019.
About 36.4% of A-levels were marked at A* and A this year, while last year, 44.8% of exams were graded A or above.
It is the first time since 2019 that A-level grades have been based on public exams, after two years of cancellations because of the Covid pandemic.
Students also received T-level, BTec and other results on Thursday.
The university admissions service, Ucas, said 65.3% of students in the UK who applied to university were offered their first choice.
This year’s A-level marking system has been adjusted, so that grades reflect “a midway point” between 2019 – when 25.4% were A* and A grades – and 2021, when teacher-assessed grades led to a boom in top marks.
England’s exam watchdog Ofqual has said the approach was intended to bring grades closer to pre-pandemic levels, while reflecting “that we are in a pandemic recovery period and students’…