SAN FRANCISCO — California teenagers, who post photographs of themselves wearing too little clothing or having had too much to drink, will have the legal right to erase their online indiscretions under newly enacted first-in-the-nation legislation.

The so-called ‘eraser bill,’ which Democratic Governor Jerry Brown signed into law this week, will require social media websites to allow California children, under age 18, to remove their own postings as of January 2015, even as top sites already allow users to delete their own posts.

The law forces companies to provide a way for minors to delete digital skeletons – rants, postings and pictures that could harm their reputations, their chances of getting into college and their employment opportunities.

James Steyer, chief executive of Common Sense Media, a San Francisco group that pushed for the measure, called it a milestone and “a really important step forward in the discussion of kids and teen privacy.”

A recent Kaplan study found that more than one out of four college-admissions officers check applicants’ Facebook profiles and perform Google searches on candidates.

“Just because you post a semi-naked picture of yourself at age 15 doesn’t mean it should haunt you for the rest of your life or prevent you from getting into college, getting a job or ruin your reputation with your peers,” Steyer said.