Tests for 11 and 14-year-olds should be abolished, and primary pupils should sit a new test at 10, the Welsh Assembly will hear next week.
A report by a task force charged by the Assembly to review methods of assessment at key stages 2 and 3 will recommend that KS2 pupils sit a new series of learning skills tests, taken in Year 5, rather than at the end of primary school. These will test literacy, numeracy and enquiry skills, and will be consolidated by teacher assessments in Year 6.
The report said: "What is envisaged here is not the resurrection of the existing statutory tests and tasks in a modified form at a different point in the pupil's experience.
"In their design, development and use, they would be directed towards a clear educational purpose: that of supporting the learner's transition from primary to secondary school."
It says that at KS3, pupils will be measured by teacher assessment alone.
This will be conducted at the end of Year 8 or start of Year 9, and will be reported to parents immediately. Testing at KS3 will be phased out over three years.
These recommendations follow six months of consultation, during which the task force canvassed opinion among teachers, parents, and unions. The recommendations will be consolidated in April, when the group, comprised of heads and teachers, as well as local and Assembly government officials, delivers its final report.
Jane Davidson, Assembly minister for education and lifelong learning, will decide whether to adopt the task force's proposals in early May.
Richard Daugherty, task force chair, believes that his conclusions will find favour even among the anti-test teacher unions.
He said: "Teachers said they would manage the transition between primary and secondary school much more easily if they weren't also preparing for tests.
"But this isn't an aptitude test. It's designed to help with the transition to secondary school."
His findings will be studied closely in England, where many educationists hope it will set a precedent for the abolition of testing across Britain.
John Bangs, head of education for the National Union of Teachers, said:
"The findings are going to be enormously influential.
"The review has been thoroughly educationally grounded, with the education of the whole child at its centre. Attempts to ignore it will prove fruitless."