Students have seen GCSE grades A* to C rise slightly this year, but top A* and A grades have edged down. The percentage of A* to C grades rose to 69%, up 0.2% from last year, but A* grades fell by 0.1%, marking the fourth consecutive year of declines in the highest grade.
Students in Northern Ireland had the best results, with 78.7% achieving A*-C grades, an increase of 0.7%.
In England, 68.8% of students scored an A*-C grade, while in Wales the percentage matched last year’s 66%.
Education Secretary Nicky Morgan said the results are evidence that "a generation of young people from all backgrounds are now securing the GCSEs that help give them the widest range of options later in life - whether looking for a rewarding job or a top apprenticeship".
Across the subjects, English and Math's saw improved results, with English A*-C grades up from 61.7% to 65.4% while maths saw grades of C and up climb 0.9% to 63.3%.
The General Secretary of the ASCL, Brian Lightman said headteachers believe there is “a lot of uncertainty" about the reliability of exam grades, saying: “We have heard from a number of schools that there are some results, particularly in maths, which were unexpected, and did not reflect the school's knowledge and assessment of those pupils."
DfE figures show England's best 500 state schools are outperforming the top 500 private schools, offering a higher points per pupil average. The NAHT commented that: "Numbers suggest that the top state schools are every bit as good as private ones, confirming what many in education have known for some time."