WASHINGTON—The Obama administration announced Saturday that it was taking steps to curb the amount of time students in public schools spend preparing for and taking standardized tests, and called for Congress to follow its lead as it rewrites the nation’s federal education laws.

The Department of Education laid out new guidelines for standardized tests, eased federal rules on testing where possible and promised new commitments to states and local governments to help them revaluate their testing programs.

The administration also called on Congress to make reducing student testing a part of its reauthorization and rewrite of the Elementary and Secondary Education Act, the law that governs federal-education policy.

The administration’s new recommendation to school districts is that testing should take up no more than 2% of classroom time. It also recommended additional transparency and parental-notification procedures.

In a weekend video announcement explaining the changes, President Barack Obama called for a holistic approach to evaluating student progress and achievement.

“Learning is about so much more than just filling in the right bubble. So we’re going to work with states, school districts, teachers, and parents to make sure that we’re not obsessing about testing, that the principles I just outlined are reflected in classrooms throughout the country—to make sure that our kids are enjoying learning, that our teachers are able to operate with creativity, to make sure we are preparing our kids for a lifetime of success,” Mr. Obama said.

The guidelines—which don’t carry the force of law—will likely get a welcome reception in Congress. Congress has been looking to rewrite the nation’s education laws recently and both conservative and progressive lawmakers have expressed a desire to make major changes in the way the federal government deals with testing.

Many conservatives object to the federal government taking more control of what have historically been education policy decisions made at the state and local levels.

The proposed rewrite of the federal education law being considered by the Senate “reverses the trend toward a national school board,” Sen. Lamar Alexander (R., Tenn.), chairman of the Health, Education, Labor and Pensions Committee, said in an interview with The Wall Street Journal over the summer.

The proposed bill crafted in the Senate keeps annual statewide tests but lets state governments decide how to best boost student achievement.

“This is common sense. It’s why overwhelming numbers of Americans think there is too much testing,” American Federation of Teachers President Randi Weingarten said in a statement. She added: “It’s why legislators on both sides of the aisle want to fix No Child Left Behind, a law that drove overtesting. The time to act is now.”

Texas and other states began instituting mandatory standardized tests for public school students.

Those guidelines were expanded to much of the country under the administration of George W. Bush, who helped push the No Child Left Behind rewrite of the Elementary and Secondary Education Act. That law expired in 2007, though its mandates remain in place.

• The most tests were required in eighth and 10th grade; the fewest were in pre-K, kindergarten and first grade.
• Four in 10 districts report having to wait between two months and four months before getting state test results.
• Some pockets of the country had substantial numbers of students opting out of standardized tests. But the overall opt-out rate was usually less than 1 %.

Write to Byron Tau at byron.tau@wsj.com