Chris Woodhead says the changes will cut teachers' workload
At present, schools are given two terms' advance notice of an inspection, which from next year will be cut to between six and ten weeks.
There have been complaints from teachers that the lengthy run-up to an inspection has caused a prolonged period of disruption, as school life for most of a year becomes dominated by getting ready for an inspection.
It has also been claimed that the long wait causes extra stress for teachers, which has a negative impact on their teaching.
There will also be changes to the form of inspections, with the introduction from January of a "lighter" inspection for the most effective schools, as the Office for Standards in Education (Ofsted) seeks to spend more time with struggling schools.
The schools' watchdog believes that about 20% of schools will qualify for a lighter inspection regime. In oder to be eligible for this "health-check" inspection, schools will need to have an improving performance in tests and exams and to have had favourable reports from Ofsted in previous inspections.
These lighter inspections will involve fewer inspectors and will take up to 60% less time than for a standard inspection.
Ofsted's chief executive, Chris Woodhead, said the "principle of external inspection is undiminished. But it has to be right to give successful schools as much room as possible to get on with the job.
"By adopting the health check style of inspection for such schools, Ofsted can keep its finger on the pulse while concentrating its resources on those schools which may be in need of more intensive care.
"These changes, especially the reduced period of notice, will also help to reduce the workload and pressure on teachers."