Students and families can compare colleges’ tuitions, the pace at which they are rising and the net cost of attending each college on a new Web site the Department of Education made public on Thursday, fulfilling a legislative mandate.

The new lists, required by the Higher Education Opportunity Act of 2008, show the institutions with the highest and lowest tuitions, the highest and lowest percentage tuition increases over the last two years, and the highest and lowest net price — that is, the actual price full-time students pay, including room and board, after financial aid like grants and scholarships are taken into account.

In each of several categories — public and private, for-profit and nonprofit, four-year and two-year — the most expensive institutions and those whose costs are rising most rapidly will be required to report to the Education Department why their costs are so high and what they plan to do about it.

“This allows students and families to see the highs and lows of the distributions and highlights those good-performing institutions,” said David Bergeron, a department official.