Girls are continuing to leave boys behind at GCSE, today's national results reveal, with more pupils sitting exams early.
Teenagers in England, Wales and Northern Ireland are receiving their GCSE grades today, and the results show that it has been another record-breaking year.
Nearly seven in 10 entries were awarded at least a C grade, and almost one in four achieved an A or A*.
In total, the A*-C pass rate rose for the 23rd year in a row.
The results, published by the Joint Council for Qualifications shows that overall, girls are still outperforming boys, continuing the trend of the last two decades.
The gender gap has widened slightly at grade A-A*. This year, 24.4% of girls' entries were awarded at least an A grade compared to 18.7% of boys' entries - a gap of 5.7%.
This has been widening since 2007, when the gap was 5.2%. And in 1989, the gap was just 1.5%.
Boys did outperform girls in maths for the second year running, the results showed, with 58.6% of boys' entries scoring at least a C compared with 58.3% of girls'.
Today's national results also reveal a huge rise in the numbers of pupils sitting their English and maths GCSEs at least a year early.
In total, some 83,000 pupils, more than one in 10, sat their maths GCSE at the age of 15 or younger - a 37% increase on 2009.
And 66,900 pupils, just under one in 10, sat their English GCSE at the age of 15 or younger - a 50% rise on last year.
The figures are likely to reignite the debate over whether GCSE exams are getting easier.
It was suggested that the trend is partly down to the last government scrapping Sats tests for 14-year-olds. The move has meant some schools now start GCSE studies a year earlier.
Dr John Dunford, general secretary of the Association of School and College Leaders (ASCL) said: "The end of the Sats tests means that schools are able to be more flexible with the Key Stage 3 curriculum and the timing of GCSEs.
"For high-achieving students, schools are able to compress the Key Stage 3 curriculum and allow them to start some GCSEs a year early. Schools are working hard to stretch their most able students and make sure that they have the opportunity to gain as many qualifications as possible. Some students are starting AS modules in year 11 and others are using the time to concentrate on other GCSE subjects."
Dr Dunford added that a "few" schools may be entering pupils for exams early so that if they fail they get another chance at the qualification.
Clara Kenyon, acting chief executive of the OCR exam board, said: "Because there is no longer testing at Key Stage 3, some schools have shortened that part of the curriculum and spend longer time studying Key Stage 4 (GCSEs), and submit candidates when they feel they are ready."
Brian Lightman, ASCL general secretary elect, said the gender gap was more to do with the examining system than what children actually learn.
Girls do better at coursework, and boys do better when sitting structured exams, he said.
The results showed that while the pass rate has risen again this year, there was another slump in the numbers of pupils taking French and German.
The numbers of pupils taking GCSEs in the three sciences - biology, chemistry and physics - has increased, although the proportion being awarded top grades has fallen.
Overall, 69.1% of all GCSE entries were awarded at least a C grade, up two percentage points on 2009. More than one in five (22.6%) entries achieved an A* or an A, up one percentage point on last year.
The rises came despite the number of entries dipping again this year - there were more than 5.37 million entries, compared with 5.47 million in 2009.
After a drop in the number of English entries being awarded a C last year, the pass rate has risen this summer. Almost two thirds (64.7%) of English entries gained at least a C grade, up from 62.7% in 2009.
In maths, 58.4% of entries achieved a C, up from 57.2% last summer.
French entries are down by 5.9%, and it has dropped out of the list of top 10 subjects for the first time.
Entries for German have also dropped by 4.5%.
Bucking the trend is Spanish, which saw a 0.9% rise.
More teenagers are also opting for other modern foreign languages - entries for Chinese are up by 5.2%, Portuguese by 9.6% and Polish by 12%.
Schools minister Nick Gibb said: "While celebrating individual success and welcoming the fact that there has been an enormous take-up of GCSEs in the individual sciences, we believe that more needs to be done to close the attainment gap between those from the poorest and wealthiest backgrounds.
"The continued success of academies in some of the most challenging areas of the country shows what can be done. We are committed to expanding the number of academies as we need to do more to raise expectations and help ensure that all children, regardless of their backgrounds, can excel."
Chris Keates, general secretary of the NASUWT teaching union said: "These are the best ever results but the worst ever outcomes now exist for young people.
"These fantastic results stand in stark contrast to some of the worst ever employment and training prospects for young people and the reality of rising youth unemployment as a result of the coalition Government's austerity programme."
Christine Blower, general secretary of the National Union of Teachers (NUT), said the results were "a massive vote of confidence in young people and their teachers" and praised the continuing improvements in the sciences as well as English and maths.
She added: "For those who criticise the GCSE, they should reflect on the negative impact that criticism has on the morale and confidence of young people. While there are strong arguments for reviewing the overall examination system, as Tomlinson did, GCSEs as they stand represent both rigour and quality and young people can be proud of the grades they have achieved."
Dr Mary Bousted, general secretary of the Association of Teachers and Lecturers (ATL), praised students for their results, but said the Government needed to take urgent action to make sure all children reached their potential.
"It is essential that education serves all young people," she said.
"The experience in the classroom of our members is that, irrespective of achievement, students are turned off by the exam culture dictated from on high.
"To succeed in education, work and life, young people need to develop useful and transferable skills, which an over-packed curriculum focused on passing tests does not provide."
She added: "ATL believes it is unacceptable for a generation of young people to be this poorly served.
"The Government must decide, and decide quickly, what the 14-16 phase of education should look like and keep students' needs, and the cultivation of a passion for learning, at the centre of all decisions. The status quo long lost its credibility."
More youngsters are opting for Religious Studies, the results showed, and is now the ninth most popular subject, up from number 11 last year.
In total, 188,704 students took the qualification.
Nick McKemey, head of school improvement for the Church of England, said: "The relentless growth of religious education as a choice for GCSE students underlines the importance of investing adequate resources and time in its teaching. Young people are clamouring for a deeper understanding of religious perspectives on issues of the day and how moral and ethical questions are considered by the major faiths.
"Twelve years of organic growth in student numbers cannot be ignored. This is a phenomenon that indicates students' appreciation that exploring faith and belief helps them to understand the world and become better global citizens."
There was also a 0.7% increase in the numbers taking history.