WASHINGTON — For eight years, the jihadi propaganda of Anwar al-Awlaki has helped shape a generation of US terrorists, including the Fort Hood gunman, the Boston Marathon bombers, and the perpetrators of massacres in San Bernardino, Calif., and Orlando.

And YouTube, the world’s most popular video site, has allowed hundreds of hours of al-Awlaki’s talks to be within easy reach of anyone with a phone or computer.

Now, under growing pressure from governments and counterterrorism advocates, YouTube has drastically reduced its video archive of Awlaki, an American cleric who remains the leading English-language jihadi recruiter on the Internet six years after he was killed by a US drone strike.

Using video fingerprinting technology, YouTube now flags his videos automatically, and human reviewers block most of them before anyone sees them, company officials say.

A search for “Anwar al-Awlaki’’ on YouTube this fall found more than 70,000 videos.

Today the same search turns up just 18,600 videos, and the vast majority are news reports about his life and death, debates over the legality of his killing, refutations of his work by scholars, or other material about him.