Parents of children with congenital heart disease can now check surgery survival rates at the UK's 16 specialist heart centres online.
Surgical teams rather than individuals are scored
The initiative comes 10 years after the inquiry into the unnecessary deaths of babies treated at Bristol's Royal Infirmary in the 1980s and 1990s.
It includes the number and range of procedures each does and survival rates for the most common surgeries.
However, the figures do not rate individual surgeons.
The figures are also not adjusted for risk, which means other factors, such as the age or sex of the child or a particularly complex case, might skew the data.
The NHS' Information Centre (IC), which runs the new website (www.ccad.org.uk/congenital), argues that data on individual surgeons would be misleading as treatment is delivered by a team rather than by an individual.
The site also includes national averages for comparison and any hospitals that appear to be failing can be flagged to the appropriate authorities, the IC added.
At least eight out of every 1,000 babies born each year have a heart defect and about half of these will need medical treatment or surgery.
Anne Keatley-Clarke, chief executive of the Children's Heart Federation, thought the website would be helpful to parents.
She said: "Parents will now be able to look at how many procedures a unit is doing and what their success rates are before making a decision about their child's treatment."
SPECIALIST HEART CENTRES
1. Liverpool: Alder Hey hospital
2. Birmingham: Children's hospital, Queen Elizabeth hospital
3. Bristol: Children's hospital
4. Newcastle Upon Tyne: Freeman hospital
5. Leicester: Glenfield hospital
6. London: The Heart Hospital, Great Ormond Street, Guys and Royal Brompton hospitals, Harley Street clinic
7. Oxford: John Radcliffe hospital
8. Leeds: General Infirmary
9. Glasgow: The Royal Hospital for Sick Children
10. Belfast: Royal Victoria hospital
11. Southampton: General Hospital
And Dr John Gibbs, president of the British Congenital Cardiac Association, said: "Open sharing of data will help to identify best practice and will contribute to the further improvement of results of treatment for our patients."
Sir Bruce Keogh, commissioner of the Healthcare Commission and president of the Society of Cardiothoracic Surgeons, said parents could be reassured that the quality of treatment in the UK was "as good, if not better, than anywhere else in the world".
Professor Peter Weissberg, medical director of the British Heart Foundation, said the new data should go a long way towards reassuring the public that the UK has now got its "house in order" over reporting outcomes of surgery for congenital heart disease.
"Patients, and particularly their parents or carers, can be reassured there is nothing to hide and they will receive a high standard of care," he added.
Heart tsar Professor Roger Boyle added: "I am sure that having this information available for parents and families will be welcomed by all concerned."
Specialists from The Society of Cardiothoracic Surgeons of Great Britain and Ireland and The British Congenital Cardiac Association helped develop the website which was funded by independent health watchdog the Healthcare Commission.