Teachers will be able to compare their pupils' results with those from schools similar to their own, thanks to a new national pupil database for Wales.
The database links information about pupils collected through January's annual school census (PLASC) with external exam results, to create educational profiles of the school population.
School staff, local authority officers, researchers, Estyn inspectors, civil servants and other stakeholders can access the site, subject to approval.
Users cannot access information on individual pupils, and the anonymity of schools is also protected, depending on who is using the database. But an email system will allow schools to share good practice.
Education and lifelong learning minister Jane Davidson, speaking at the launch of the database at Burry Port junior school, Carmarthenshire, said:
"It aims to promote the recognition and sharing of good practice, to support self-evaluation and development, and encourage the use of data in the drive to raise standards.
"The database will provide a research tool for developing policy and help us consider the impact of strategic decisions over time."